Hi Everyone, I have a Dell R210 server which has a Xeon X3430 Quad Core CPU (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller in a RAID1 setup How many VMs do you think I''d be able to run on this machine? Is 20 pushing it? I''d say most (if not all) guests would be in PV mode. Thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Le samedi 05 juin 2010 à 23:54 +0100, Jonathan Tripathy a écrit :> Hi Everyone, > > I have a Dell R210 server which has a Xeon X3430 Quad Core CPU (2.4Ghz x > 4) with 8GB of RAM. I intend to use the H200 controller in a RAID1 setup > > How many VMs do you think I''d be able to run on this machine? Is 20 > pushing it? > > I''d say most (if not all) guests would be in PV mode. >Hello, The number of VMs you can run is directly limited by the memory needed for each VM. If you have 8Gb, reserve at lease 1Gb for the Domain-0, so there are 7Gb left, if your VMs are 1 GB each you can run #7 VMs. If the load of each VM is high you will be limited by the processing power. Regards, JPPO _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sunday 06 June 2010 11:03:57 jpp@jppozzi.dyndns.org wrote:> Le samedi 05 juin 2010 à 23:54 +0100, Jonathan Tripathy a écrit : > > Hi Everyone, > > > > I have a Dell R210 server which has a Xeon X3430 Quad Core CPU (2.4Ghz x > > 4) with 8GB of RAM. I intend to use the H200 controller in a RAID1 setup > > > > How many VMs do you think I''d be able to run on this machine? Is 20 > > pushing it? > > > > I''d say most (if not all) guests would be in PV mode. > > Hello, > > The number of VMs you can run is directly limited by the memory needed > for each VM. If you have 8Gb, reserve at lease 1Gb for the Domain-0, so > there are 7Gb left, if your VMs are 1 GB each you can run #7 VMs. > If the load of each VM is high you will be limited by the processing > power. > > Regards, > > JPPO > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >Storage could be a dealbreaker as well. RAID1 is not particularly ideal for fast I/O. Predicting how many you can accomodate is really diificult. Indeed memory is an issue, but they all will need to be able to access storage fast enough. Guests with high wait times will perform too slowly. B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Storage could be a dealbreaker as well. RAID1 is not particularly ideal for> fast I/O. Predicting how many you can accomodate is really diificult. > Indeed > memory is an issue, but they all will need to be able to access storage > fast > enough. Guests with high wait times will perform too slowly. > >What level of RAID do you suggest? I am currently using RAID 1 and your correct in saying that hosts are slow on disk I/O, I plan to use RAID 10 next W _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sunday 06 June 2010 12:16:49 william pink wrote:> Storage could be a dealbreaker as well. RAID1 is not particularly ideal for > > > fast I/O. Predicting how many you can accomodate is really diificult. > > Indeed > > memory is an issue, but they all will need to be able to access storage > > fast > > enough. Guests with high wait times will perform too slowly. > > What level of RAID do you suggest? I am currently using RAID 1 and your > correct in saying that hosts are slow on disk I/O, I plan to use RAID 10 > next > > W >For faster read I/O RAID5, RAID6 or RAID50 are better. For faster write I/O you want RAID0 or RAID10. I find RAID50 a good comprise in between both, since at has a low penalty on the disk number. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Jonathan, the question is, what a kind of VM? You can over-utilize a much greater machine with one VM. Or on the other side, you can run 40 VMs on a shorter machine. Each ressource can be a bottleneck - Memory - this is realy easy to calculate: Avaiable minus 768MB (Reserved for Dom0 should be enugh in this case). - CPU - Here we need a VM statistic - Disk Bandwidth - Here we need a VM statistic, but in the most cases not the bottleneck - Disk IOPS - Here we need a VM statistic, in the most cases the botelneck What a kind of VMs you plane to run? Webservers / mailservers / database-servers ...? Best Regards Michael Schmidt Am 06.06.10 00:54, schrieb Jonathan Tripathy:> Hi Everyone, > > I have a Dell R210 server which has a Xeon X3430 Quad Core CPU (2.4Ghz > x 4) with 8GB of RAM. I intend to use the H200 controller in a RAID1 > setup > > How many VMs do you think I''d be able to run on this machine? Is 20 > pushing it? > > I''d say most (if not all) guests would be in PV mode. > > Thanks > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Michael, Thanks for your email. This is just an idea that I have floating around in my head that maybe I''d like to rent out some VPSs to customers, just to utilise my machine which will be sitting in a co-lo nearly idle. I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. So the answer is, I don''t know what will be running on them, however I could write up an "acceptable use policy", as well as use some throttling/scheduling? Thanks On 06/06/10 19:39, Michael Schmidt wrote:> Hi Jonathan, > > the question is, what a kind of VM? > You can over-utilize a much greater machine with one VM. > Or on the other side, you can run 40 VMs on a shorter machine. > > Each ressource can be a bottleneck > > - Memory - this is realy easy to calculate: Avaiable minus 768MB > (Reserved for Dom0 should be enugh in this case). > - CPU - Here we need a VM statistic > - Disk Bandwidth - Here we need a VM statistic, but in the most cases > not the bottleneck > - Disk IOPS - Here we need a VM statistic, in the most cases the > botelneck > > What a kind of VMs you plane to run? > Webservers / mailservers / database-servers ...? > > Best Regards > > Michael Schmidt > > > Am 06.06.10 00:54, schrieb Jonathan Tripathy: >> Hi Everyone, >> >> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller in >> a RAID1 setup >> >> How many VMs do you think I''d be able to run on this machine? Is 20 >> pushing it? >> >> I''d say most (if not all) guests would be in PV mode. >> >> Thanks >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Jonathan, if you plan to migrate existing physical machines to xen VMs, or you have some different machines for a comparison, you can easy get runtime statistics and calculate the usage. Look at the running iostats and cpu usage. If you plan to rent generic VMs on this server to customers, you disk / raid setup will be absolutely the bottleneck. A solution at this point is not easy. If you have much write IOs, use raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the same amount of disks. In each case i can suggest you 15k rpm SAS disks. Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. But note: You cannot set disk priority to the VMs. So if one VM does heavy disk IO, all off the other VMs slowed down. Best Regards Michael Schmidt Am 06.06.10 20:45, schrieb Jonathan Tripathy:> Hi Michael, > > Thanks for your email. > > This is just an idea that I have floating around in my head that maybe > I''d like to rent out some VPSs to customers, just to utilise my > machine which will be sitting in a co-lo nearly idle. > > I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. > > So the answer is, I don''t know what will be running on them, however I > could write up an "acceptable use policy", as well as use some > throttling/scheduling? > > Thanks > > On 06/06/10 19:39, Michael Schmidt wrote: >> Hi Jonathan, >> >> the question is, what a kind of VM? >> You can over-utilize a much greater machine with one VM. >> Or on the other side, you can run 40 VMs on a shorter machine. >> >> Each ressource can be a bottleneck >> >> - Memory - this is realy easy to calculate: Avaiable minus 768MB >> (Reserved for Dom0 should be enugh in this case). >> - CPU - Here we need a VM statistic >> - Disk Bandwidth - Here we need a VM statistic, but in the most cases >> not the bottleneck >> - Disk IOPS - Here we need a VM statistic, in the most cases the >> botelneck >> >> What a kind of VMs you plane to run? >> Webservers / mailservers / database-servers ...? >> >> Best Regards >> >> Michael Schmidt >> >> >> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>> Hi Everyone, >>> >>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller in >>> a RAID1 setup >>> >>> How many VMs do you think I''d be able to run on this machine? Is 20 >>> pushing it? >>> >>> I''d say most (if not all) guests would be in PV mode. >>> >>> Thanks >>> >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks Micael, I understand what you are saying. With a small setup such as a RAID1 array, how many VMs could I rent out? It doesn''t matter if it''s a small number, it''s just to utilise the server a bit. Think it would cope with 5-10? Thanks Jonathan On 06/06/10 20:18, Michael Schmidt wrote:> Hi Jonathan, > > if you plan to migrate existing physical machines to xen VMs, or you > have some different machines for a comparison, > you can easy get runtime statistics and calculate the usage. Look at > the running iostats and cpu usage. > > If you plan to rent generic VMs on this server to customers, you disk > / raid setup will be absolutely the bottleneck. > A solution at this point is not easy. If you have much write IOs, use > raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the > same amount of disks. > In each case i can suggest you 15k rpm SAS disks. > > Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > > But note: You cannot set disk priority to the VMs. So if one VM does > heavy disk IO, all off the other VMs slowed down. > > Best Regards > > Michael Schmidt > > > Am 06.06.10 20:45, schrieb Jonathan Tripathy: >> Hi Michael, >> >> Thanks for your email. >> >> This is just an idea that I have floating around in my head that >> maybe I''d like to rent out some VPSs to customers, just to utilise my >> machine which will be sitting in a co-lo nearly idle. >> >> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >> >> So the answer is, I don''t know what will be running on them, however >> I could write up an "acceptable use policy", as well as use some >> throttling/scheduling? >> >> Thanks >> >> On 06/06/10 19:39, Michael Schmidt wrote: >>> Hi Jonathan, >>> >>> the question is, what a kind of VM? >>> You can over-utilize a much greater machine with one VM. >>> Or on the other side, you can run 40 VMs on a shorter machine. >>> >>> Each ressource can be a bottleneck >>> >>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>> (Reserved for Dom0 should be enugh in this case). >>> - CPU - Here we need a VM statistic >>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>> cases not the bottleneck >>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>> botelneck >>> >>> What a kind of VMs you plane to run? >>> Webservers / mailservers / database-servers ...? >>> >>> Best Regards >>> >>> Michael Schmidt >>> >>> >>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>> Hi Everyone, >>>> >>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>> in a RAID1 setup >>>> >>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>> pushing it? >>>> >>>> I''d say most (if not all) guests would be in PV mode. >>>> >>>> Thanks >>>> >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
RAID1 does not perform better than a single disk. It will still depend on what those 5 to 10 VMs would do. It still might be stretching it. For 10 webservers visited by 5 users per hour: I would say no problem. For 5 heavily used database servers it will be another story. I guess the only real way to find out is to put your guests on there and try. If you clone them, you will know quite fast. On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote:> Thanks Micael, > > I understand what you are saying. > > With a small setup such as a RAID1 array, how many VMs could I rent out? > > It doesn''t matter if it''s a small number, it''s just to utilise the > server a bit. > > Think it would cope with 5-10? > > Thanks > > Jonathan > > On 06/06/10 20:18, Michael Schmidt wrote: > > Hi Jonathan, > > > > if you plan to migrate existing physical machines to xen VMs, or you > > have some different machines for a comparison, > > you can easy get runtime statistics and calculate the usage. Look at > > the running iostats and cpu usage. > > > > If you plan to rent generic VMs on this server to customers, you disk > > / raid setup will be absolutely the bottleneck. > > A solution at this point is not easy. If you have much write IOs, use > > raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the > > same amount of disks. > > In each case i can suggest you 15k rpm SAS disks. > > > > Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > > > > But note: You cannot set disk priority to the VMs. So if one VM does > > heavy disk IO, all off the other VMs slowed down. > > > > Best Regards > > > > Michael Schmidt > > > > Am 06.06.10 20:45, schrieb Jonathan Tripathy: > >> Hi Michael, > >> > >> Thanks for your email. > >> > >> This is just an idea that I have floating around in my head that > >> maybe I''d like to rent out some VPSs to customers, just to utilise my > >> machine which will be sitting in a co-lo nearly idle. > >> > >> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. > >> > >> So the answer is, I don''t know what will be running on them, however > >> I could write up an "acceptable use policy", as well as use some > >> throttling/scheduling? > >> > >> Thanks > >> > >> On 06/06/10 19:39, Michael Schmidt wrote: > >>> Hi Jonathan, > >>> > >>> the question is, what a kind of VM? > >>> You can over-utilize a much greater machine with one VM. > >>> Or on the other side, you can run 40 VMs on a shorter machine. > >>> > >>> Each ressource can be a bottleneck > >>> > >>> - Memory - this is realy easy to calculate: Avaiable minus 768MB > >>> (Reserved for Dom0 should be enugh in this case). > >>> - CPU - Here we need a VM statistic > >>> - Disk Bandwidth - Here we need a VM statistic, but in the most > >>> cases not the bottleneck > >>> - Disk IOPS - Here we need a VM statistic, in the most cases the > >>> botelneck > >>> > >>> What a kind of VMs you plane to run? > >>> Webservers / mailservers / database-servers ...? > >>> > >>> Best Regards > >>> > >>> Michael Schmidt > >>> > >>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: > >>>> Hi Everyone, > >>>> > >>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU > >>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller > >>>> in a RAID1 setup > >>>> > >>>> How many VMs do you think I''d be able to run on this machine? Is 20 > >>>> pushing it? > >>>> > >>>> I''d say most (if not all) guests would be in PV mode. > >>>> > >>>> Thanks > >>>> > >>>> _______________________________________________ > >>>> Xen-users mailing list > >>>> Xen-users@lists.xensource.com > >>>> http://lists.xensource.com/xen-users > >> > >> _______________________________________________ > >> Xen-users mailing list > >> Xen-users@lists.xensource.com > >> http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
If I were to install a RAID10 array, would it be ok if I connected it to my Xen host via gigabit ethernet? On 06/06/10 22:21, Bart Coninckx wrote:> RAID1 does not perform better than a single disk. It will still depend on what > those 5 to 10 VMs would do. It still might be stretching it. For 10 webservers > visited by 5 users per hour: I would say no problem. For 5 heavily used > database servers it will be another story. > > I guess the only real way to find out is to put your guests on there and try. > If you clone them, you will know quite fast. > > > On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > >> Thanks Micael, >> >> I understand what you are saying. >> >> With a small setup such as a RAID1 array, how many VMs could I rent out? >> >> It doesn''t matter if it''s a small number, it''s just to utilise the >> server a bit. >> >> Think it would cope with 5-10? >> >> Thanks >> >> Jonathan >> >> On 06/06/10 20:18, Michael Schmidt wrote: >> >>> Hi Jonathan, >>> >>> if you plan to migrate existing physical machines to xen VMs, or you >>> have some different machines for a comparison, >>> you can easy get runtime statistics and calculate the usage. Look at >>> the running iostats and cpu usage. >>> >>> If you plan to rent generic VMs on this server to customers, you disk >>> / raid setup will be absolutely the bottleneck. >>> A solution at this point is not easy. If you have much write IOs, use >>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>> same amount of disks. >>> In each case i can suggest you 15k rpm SAS disks. >>> >>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>> >>> But note: You cannot set disk priority to the VMs. So if one VM does >>> heavy disk IO, all off the other VMs slowed down. >>> >>> Best Regards >>> >>> Michael Schmidt >>> >>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>> >>>> Hi Michael, >>>> >>>> Thanks for your email. >>>> >>>> This is just an idea that I have floating around in my head that >>>> maybe I''d like to rent out some VPSs to customers, just to utilise my >>>> machine which will be sitting in a co-lo nearly idle. >>>> >>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >>>> >>>> So the answer is, I don''t know what will be running on them, however >>>> I could write up an "acceptable use policy", as well as use some >>>> throttling/scheduling? >>>> >>>> Thanks >>>> >>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>> >>>>> Hi Jonathan, >>>>> >>>>> the question is, what a kind of VM? >>>>> You can over-utilize a much greater machine with one VM. >>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>> >>>>> Each ressource can be a bottleneck >>>>> >>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>> (Reserved for Dom0 should be enugh in this case). >>>>> - CPU - Here we need a VM statistic >>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>> cases not the bottleneck >>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>> botelneck >>>>> >>>>> What a kind of VMs you plane to run? >>>>> Webservers / mailservers / database-servers ...? >>>>> >>>>> Best Regards >>>>> >>>>> Michael Schmidt >>>>> >>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>> >>>>>> Hi Everyone, >>>>>> >>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>> in a RAID1 setup >>>>>> >>>>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>>>> pushing it? >>>>>> >>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>> >>>>>> Thanks >>>>>> >>>>>> _______________________________________________ >>>>>> Xen-users mailing list >>>>>> Xen-users@lists.xensource.com >>>>>> http://lists.xensource.com/xen-users >>>>>> >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >>>> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> >>_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Yup indeed I am. My Xen host only has space for 2 drives, so I''d need a seperate storage server with more slots and expose it via iSCSI or something On 06/06/10 23:12, Bart Coninckx wrote:> > I''m confused: how are you going to connect a RAID10 via a network? Are > you talking about a seperate storage server? > > ----- Original message ----- > > If I were to install a RAID10 array, would it be ok if I connected > it to > > my Xen host via gigabit ethernet? > > > > > > On 06/06/10 22:21, Bart Coninckx wrote: > > > RAID1 does not perform better than a single disk. It will still > depend on what > > > those 5 to 10 VMs would do. It still might be stretching it. For > 10 webservers > > > visited by 5 users per hour: I would say no problem. For 5 heavily > used > > > database servers it will be another story. > > > > > > I guess the only real way to find out is to put your guests on > there and try. > > > If you clone them, you will know quite fast. > > > > > > > > > On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > > > > > > > Thanks Micael, > > > > > > > > I understand what you are saying. > > > > > > > > With a small setup such as a RAID1 array, how many VMs could I > rent out? > > > > > > > > It doesn''t matter if it''s a small number, it''s just to utilise the > > > > server a bit. > > > > > > > > Think it would cope with 5-10? > > > > > > > > Thanks > > > > > > > > Jonathan > > > > > > > > On 06/06/10 20:18, Michael Schmidt wrote: > > > > > > > > > Hi Jonathan, > > > > > > > > > > if you plan to migrate existing physical machines to xen VMs, > or you > > > > > have some different machines for a comparison, > > > > > you can easy get runtime statistics and calculate the usage. > Look at > > > > > the running iostats and cpu usage. > > > > > > > > > > If you plan to rent generic VMs on this server to customers, > you disk > > > > > / raid setup will be absolutely the bottleneck. > > > > > A solution at this point is not easy. If you have much write > IOs, use > > > > > raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with > the > > > > > same amount of disks. > > > > > In each case i can suggest you 15k rpm SAS disks. > > > > > > > > > > Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > > > > > > > > > > But note: You cannot set disk priority to the VMs. So if one > VM does > > > > > heavy disk IO, all off the other VMs slowed down. > > > > > > > > > > Best Regards > > > > > > > > > > Michael Schmidt > > > > > > > > > > Am 06.06.10 20:45, schrieb Jonathan Tripathy: > > > > > > > > > > > Hi Michael, > > > > > > > > > > > > Thanks for your email. > > > > > > > > > > > > This is just an idea that I have floating around in my head > that > > > > > > maybe I''d like to rent out some VPSs to customers, just to > utilise my > > > > > > machine which will be sitting in a co-lo nearly idle. > > > > > > > > > > > > I''d give out VPSs with 256MB RAM and probably 5Mbps > connection speed. > > > > > > > > > > > > So the answer is, I don''t know what will be running on them, > however > > > > > > I could write up an "acceptable use policy", as well as use > some > > > > > > throttling/scheduling? > > > > > > > > > > > > Thanks > > > > > > > > > > > > On 06/06/10 19:39, Michael Schmidt wrote: > > > > > > > > > > > > > Hi Jonathan, > > > > > > > > > > > > > > the question is, what a kind of VM? > > > > > > > You can over-utilize a much greater machine with one VM. > > > > > > > Or on the other side, you can run 40 VMs on a shorter > machine. > > > > > > > > > > > > > > Each ressource can be a bottleneck > > > > > > > > > > > > > > - Memory - this is realy easy to calculate: Avaiable minus > 768MB > > > > > > > (Reserved for Dom0 should be enugh in this case). > > > > > > > - CPU - Here we need a VM statistic > > > > > > > - Disk Bandwidth - Here we need a VM statistic, but in the > most > > > > > > > cases not the bottleneck > > > > > > > - Disk IOPS - Here we need a VM statistic, in the most > cases the > > > > > > > botelneck > > > > > > > > > > > > > > What a kind of VMs you plane to run? > > > > > > > Webservers / mailservers / database-servers ...? > > > > > > > > > > > > > > Best Regards > > > > > > > > > > > > > > Michael Schmidt > > > > > > > > > > > > > > Am 06.06.10 00:54, schrieb Jonathan Tripathy: > > > > > > > > > > > > > > > Hi Everyone, > > > > > > > > > > > > > > > > I have a Dell R210 server which has a Xeon X3430 Quad > Core CPU > > > > > > > > (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 > controller > > > > > > > > in a RAID1 setup > > > > > > > > > > > > > > > > How many VMs do you think I''d be able to run on this > machine? Is 20 > > > > > > > > pushing it? > > > > > > > > > > > > > > > > I''d say most (if not all) guests would be in PV mode. > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > Xen-users mailing list > > > > > > > > Xen-users@lists.xensource.com > <mailto:Xen-users@lists.xensource.com> > > > > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > > > > > _______________________________________________ > > > > > > Xen-users mailing list > > > > > > Xen-users@lists.xensource.com > <mailto:Xen-users@lists.xensource.com> > > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > _______________________________________________ > > > > Xen-users mailing list > > > > Xen-users@lists.xensource.com > <mailto:Xen-users@lists.xensource.com> > > > > http://lists.xensource.com/xen-users > > > > > > > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I''m confused: how are you going to connect a RAID10 via a network? Are you talking about a seperate storage server? ----- Original message -----> If I were to install a RAID10 array, would it be ok if I connected it to > my Xen host via gigabit ethernet? > > > On 06/06/10 22:21, Bart Coninckx wrote: > > RAID1 does not perform better than a single disk. It will still depend on what > > those 5 to 10 VMs would do. It still might be stretching it. For 10 webservers > > visited by 5 users per hour: I would say no problem. For 5 heavily used > > database servers it will be another story. > > > > I guess the only real way to find out is to put your guests on there and try. > > If you clone them, you will know quite fast. > > > > > > On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > > > > > Thanks Micael, > > > > > > I understand what you are saying. > > > > > > With a small setup such as a RAID1 array, how many VMs could I rent out? > > > > > > It doesn''t matter if it''s a small number, it''s just to utilise the > > > server a bit. > > > > > > Think it would cope with 5-10? > > > > > > Thanks > > > > > > Jonathan > > > > > > On 06/06/10 20:18, Michael Schmidt wrote: > > > > > > > Hi Jonathan, > > > > > > > > if you plan to migrate existing physical machines to xen VMs, or you > > > > have some different machines for a comparison, > > > > you can easy get runtime statistics and calculate the usage. Look at > > > > the running iostats and cpu usage. > > > > > > > > If you plan to rent generic VMs on this server to customers, you disk > > > > / raid setup will be absolutely the bottleneck. > > > > A solution at this point is not easy. If you have much write IOs, use > > > > raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the > > > > same amount of disks. > > > > In each case i can suggest you 15k rpm SAS disks. > > > > > > > > Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > > > > > > > > But note: You cannot set disk priority to the VMs. So if one VM does > > > > heavy disk IO, all off the other VMs slowed down. > > > > > > > > Best Regards > > > > > > > > Michael Schmidt > > > > > > > > Am 06.06.10 20:45, schrieb Jonathan Tripathy: > > > > > > > > > Hi Michael, > > > > > > > > > > Thanks for your email. > > > > > > > > > > This is just an idea that I have floating around in my head that > > > > > maybe I''d like to rent out some VPSs to customers, just to utilise my > > > > > machine which will be sitting in a co-lo nearly idle. > > > > > > > > > > I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. > > > > > > > > > > So the answer is, I don''t know what will be running on them, however > > > > > I could write up an "acceptable use policy", as well as use some > > > > > throttling/scheduling? > > > > > > > > > > Thanks > > > > > > > > > > On 06/06/10 19:39, Michael Schmidt wrote: > > > > > > > > > > > Hi Jonathan, > > > > > > > > > > > > the question is, what a kind of VM? > > > > > > You can over-utilize a much greater machine with one VM. > > > > > > Or on the other side, you can run 40 VMs on a shorter machine. > > > > > > > > > > > > Each ressource can be a bottleneck > > > > > > > > > > > > - Memory - this is realy easy to calculate: Avaiable minus 768MB > > > > > > (Reserved for Dom0 should be enugh in this case). > > > > > > - CPU - Here we need a VM statistic > > > > > > - Disk Bandwidth - Here we need a VM statistic, but in the most > > > > > > cases not the bottleneck > > > > > > - Disk IOPS - Here we need a VM statistic, in the most cases the > > > > > > botelneck > > > > > > > > > > > > What a kind of VMs you plane to run? > > > > > > Webservers / mailservers / database-servers ...? > > > > > > > > > > > > Best Regards > > > > > > > > > > > > Michael Schmidt > > > > > > > > > > > > Am 06.06.10 00:54, schrieb Jonathan Tripathy: > > > > > > > > > > > > > Hi Everyone, > > > > > > > > > > > > > > I have a Dell R210 server which has a Xeon X3430 Quad Core CPU > > > > > > > (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller > > > > > > > in a RAID1 setup > > > > > > > > > > > > > > How many VMs do you think I''d be able to run on this machine? Is 20 > > > > > > > pushing it? > > > > > > > > > > > > > > I''d say most (if not all) guests would be in PV mode. > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > _______________________________________________ > > > > > > > Xen-users mailing list > > > > > > > Xen-users@lists.xensource.com > > > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > > > _______________________________________________ > > > > > Xen-users mailing list > > > > > Xen-users@lists.xensource.com > > > > > http://lists.xensource.com/xen-users > > > > > > > > _______________________________________________ > > > Xen-users mailing list > > > Xen-users@lists.xensource.com > > > http://lists.xensource.com/xen-users > > > > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I see. Gigabit gives you about 110MB per second. What your RAID gives you is depending of your disks (sata, sas, 10k, 15k). I recently did throughput test on RAID5 and this resulted in 120MB per second on 10k sas disks. But as stated before it''s really the IOPS that count. I think you will be better of with two bonded gigabit nicd in mode0. ----- Original message -----> Yup indeed I am. > > My Xen host only has space for 2 drives, so I''d need a seperate storage > server with more slots and expose it via iSCSI or something > > On 06/06/10 23:12, Bart Coninckx wrote: > > > > I''m confused: how are you going to connect a RAID10 via a network? Are > > you talking about a seperate storage server? > > > > ----- Original message ----- > > > If I were to install a RAID10 array, would it be ok if I connected > > it to > > > my Xen host via gigabit ethernet? > > > > > > > > > On 06/06/10 22:21, Bart Coninckx wrote: > > > > RAID1 does not perform better than a single disk. It will still > > depend on what > > > > those 5 to 10 VMs would do. It still might be stretching it. For > > 10 webservers > > > > visited by 5 users per hour: I would say no problem. For 5 heavily > > used > > > > database servers it will be another story. > > > > > > > > I guess the only real way to find out is to put your guests on > > there and try. > > > > If you clone them, you will know quite fast. > > > > > > > > > > > > On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > > > > > > > > > Thanks Micael, > > > > > > > > > > I understand what you are saying. > > > > > > > > > > With a small setup such as a RAID1 array, how many VMs could I > > rent out? > > > > > > > > > > It doesn''t matter if it''s a small number, it''s just to utilise the > > > > > server a bit. > > > > > > > > > > Think it would cope with 5-10? > > > > > > > > > > Thanks > > > > > > > > > > Jonathan > > > > > > > > > > On 06/06/10 20:18, Michael Schmidt wrote: > > > > > > > > > > > Hi Jonathan, > > > > > > > > > > > > if you plan to migrate existing physical machines to xen VMs, > > or you > > > > > > have some different machines for a comparison, > > > > > > you can easy get runtime statistics and calculate the usage. > > Look at > > > > > > the running iostats and cpu usage. > > > > > > > > > > > > If you plan to rent generic VMs on this server to customers, > > you disk > > > > > > / raid setup will be absolutely the bottleneck. > > > > > > A solution at this point is not easy. If you have much write > > IOs, use > > > > > > raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with > > the > > > > > > same amount of disks. > > > > > > In each case i can suggest you 15k rpm SAS disks. > > > > > > > > > > > > Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > > > > > > > > > > > > But note: You cannot set disk priority to the VMs. So if one > > VM does > > > > > > heavy disk IO, all off the other VMs slowed down. > > > > > > > > > > > > Best Regards > > > > > > > > > > > > Michael Schmidt > > > > > > > > > > > > Am 06.06.10 20:45, schrieb Jonathan Tripathy: > > > > > > > > > > > > > Hi Michael, > > > > > > > > > > > > > > Thanks for your email. > > > > > > > > > > > > > > This is just an idea that I have floating around in my head > > that > > > > > > > maybe I''d like to rent out some VPSs to customers, just to > > utilise my > > > > > > > machine which will be sitting in a co-lo nearly idle. > > > > > > > > > > > > > > I''d give out VPSs with 256MB RAM and probably 5Mbps > > connection speed. > > > > > > > > > > > > > > So the answer is, I don''t know what will be running on them, > > however > > > > > > > I could write up an "acceptable use policy", as well as use > > some > > > > > > > throttling/scheduling? > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > On 06/06/10 19:39, Michael Schmidt wrote: > > > > > > > > > > > > > > > Hi Jonathan, > > > > > > > > > > > > > > > > the question is, what a kind of VM? > > > > > > > > You can over-utilize a much greater machine with one VM. > > > > > > > > Or on the other side, you can run 40 VMs on a shorter > > machine. > > > > > > > > > > > > > > > > Each ressource can be a bottleneck > > > > > > > > > > > > > > > > - Memory - this is realy easy to calculate: Avaiable minus > > 768MB > > > > > > > > (Reserved for Dom0 should be enugh in this case). > > > > > > > > - CPU - Here we need a VM statistic > > > > > > > > - Disk Bandwidth - Here we need a VM statistic, but in the > > most > > > > > > > > cases not the bottleneck > > > > > > > > - Disk IOPS - Here we need a VM statistic, in the most > > cases the > > > > > > > > botelneck > > > > > > > > > > > > > > > > What a kind of VMs you plane to run? > > > > > > > > Webservers / mailservers / database-servers ...? > > > > > > > > > > > > > > > > Best Regards > > > > > > > > > > > > > > > > Michael Schmidt > > > > > > > > > > > > > > > > Am 06.06.10 00:54, schrieb Jonathan Tripathy: > > > > > > > > > > > > > > > > > Hi Everyone, > > > > > > > > > > > > > > > > > > I have a Dell R210 server which has a Xeon X3430 Quad > > Core CPU > > > > > > > > > (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 > > controller > > > > > > > > > in a RAID1 setup > > > > > > > > > > > > > > > > > > How many VMs do you think I''d be able to run on this > > machine? Is 20 > > > > > > > > > pushing it? > > > > > > > > > > > > > > > > > > I''d say most (if not all) guests would be in PV mode. > > > > > > > > > > > > > > > > > > Thanks > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > > > Xen-users mailing list > > > > > > > > > Xen-users@lists.xensource.com > > <mailto:Xen-users@lists.xensource.com> > > > > > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > > > > > > > _______________________________________________ > > > > > > > Xen-users mailing list > > > > > > > Xen-users@lists.xensource.com > > <mailto:Xen-users@lists.xensource.com> > > > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > > > _______________________________________________ > > > > > Xen-users mailing list > > > > > Xen-users@lists.xensource.com > > <mailto:Xen-users@lists.xensource.com> > > > > > http://lists.xensource.com/xen-users > > > > > > > > > > > >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
This is not completely correct. With a raid 1, you have the read performance of 2 disks and just the write performance of a single disk. To the other thinks following this thread: If you use a network storage, you have a bandwidth limit with the connection. But in the most cases, the raw bandwidth is not the bottleneck (instead of the IOs per second). Network Storages using NFS or NBD are not stable enough in my eyes. iSCSI and FC SANs but really stable and expansive as well. But there is another much less expensive way: You get the most servers with an external SAS port. There you can connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). This disks can be managed by the servers raid controller. Best Regards Michael Schmidt Am 06.06.10 23:21, schrieb Bart Coninckx:> RAID1 does not perform better than a single disk. It will still depend on what > those 5 to 10 VMs would do. It still might be stretching it. For 10 webservers > visited by 5 users per hour: I would say no problem. For 5 heavily used > database servers it will be another story. > > I guess the only real way to find out is to put your guests on there and try. > If you clone them, you will know quite fast. > > > On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > >> Thanks Micael, >> >> I understand what you are saying. >> >> With a small setup such as a RAID1 array, how many VMs could I rent out? >> >> It doesn''t matter if it''s a small number, it''s just to utilise the >> server a bit. >> >> Think it would cope with 5-10? >> >> Thanks >> >> Jonathan >> >> On 06/06/10 20:18, Michael Schmidt wrote: >> >>> Hi Jonathan, >>> >>> if you plan to migrate existing physical machines to xen VMs, or you >>> have some different machines for a comparison, >>> you can easy get runtime statistics and calculate the usage. Look at >>> the running iostats and cpu usage. >>> >>> If you plan to rent generic VMs on this server to customers, you disk >>> / raid setup will be absolutely the bottleneck. >>> A solution at this point is not easy. If you have much write IOs, use >>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>> same amount of disks. >>> In each case i can suggest you 15k rpm SAS disks. >>> >>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>> >>> But note: You cannot set disk priority to the VMs. So if one VM does >>> heavy disk IO, all off the other VMs slowed down. >>> >>> Best Regards >>> >>> Michael Schmidt >>> >>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>> >>>> Hi Michael, >>>> >>>> Thanks for your email. >>>> >>>> This is just an idea that I have floating around in my head that >>>> maybe I''d like to rent out some VPSs to customers, just to utilise my >>>> machine which will be sitting in a co-lo nearly idle. >>>> >>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >>>> >>>> So the answer is, I don''t know what will be running on them, however >>>> I could write up an "acceptable use policy", as well as use some >>>> throttling/scheduling? >>>> >>>> Thanks >>>> >>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>> >>>>> Hi Jonathan, >>>>> >>>>> the question is, what a kind of VM? >>>>> You can over-utilize a much greater machine with one VM. >>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>> >>>>> Each ressource can be a bottleneck >>>>> >>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>> (Reserved for Dom0 should be enugh in this case). >>>>> - CPU - Here we need a VM statistic >>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>> cases not the bottleneck >>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>> botelneck >>>>> >>>>> What a kind of VMs you plane to run? >>>>> Webservers / mailservers / database-servers ...? >>>>> >>>>> Best Regards >>>>> >>>>> Michael Schmidt >>>>> >>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>> >>>>>> Hi Everyone, >>>>>> >>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>> in a RAID1 setup >>>>>> >>>>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>>>> pushing it? >>>>>> >>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>> >>>>>> Thanks >>>>>> >>>>>> _______________________________________________ >>>>>> Xen-users mailing list >>>>>> Xen-users@lists.xensource.com >>>>>> http://lists.xensource.com/xen-users >>>>>> >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >>>> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users >> >> > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Michael, You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly free? I agree with you that Fibre Channel systems are very expensive Would iSCSI over IP be ok? Thanks On 07/06/10 08:12, Michael Schmidt wrote:> This is not completely correct. > With a raid 1, you have the read performance of 2 disks and just the > write performance of a single disk. > > To the other thinks following this thread: > If you use a network storage, you have a bandwidth limit with the > connection. But in the most cases, the raw bandwidth is not the > bottleneck (instead of the IOs per second). > > Network Storages using NFS or NBD are not stable enough in my eyes. > iSCSI and FC SANs but really stable and expansive as well. But there > is another much less expensive way: > > You get the most servers with an external SAS port. There you can > connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). > This disks can be managed by the servers raid controller. > > Best Regards > > Michael Schmidt > > > Am 06.06.10 23:21, schrieb Bart Coninckx: >> RAID1 does not perform better than a single disk. It will still >> depend on what >> those 5 to 10 VMs would do. It still might be stretching it. For 10 >> webservers >> visited by 5 users per hour: I would say no problem. For 5 heavily used >> database servers it will be another story. >> >> I guess the only real way to find out is to put your guests on there >> and try. >> If you clone them, you will know quite fast. >> >> >> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: >>> Thanks Micael, >>> >>> I understand what you are saying. >>> >>> With a small setup such as a RAID1 array, how many VMs could I rent >>> out? >>> >>> It doesn''t matter if it''s a small number, it''s just to utilise the >>> server a bit. >>> >>> Think it would cope with 5-10? >>> >>> Thanks >>> >>> Jonathan >>> >>> On 06/06/10 20:18, Michael Schmidt wrote: >>>> Hi Jonathan, >>>> >>>> if you plan to migrate existing physical machines to xen VMs, or you >>>> have some different machines for a comparison, >>>> you can easy get runtime statistics and calculate the usage. Look at >>>> the running iostats and cpu usage. >>>> >>>> If you plan to rent generic VMs on this server to customers, you disk >>>> / raid setup will be absolutely the bottleneck. >>>> A solution at this point is not easy. If you have much write IOs, use >>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>>> same amount of disks. >>>> In each case i can suggest you 15k rpm SAS disks. >>>> >>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>>> >>>> But note: You cannot set disk priority to the VMs. So if one VM does >>>> heavy disk IO, all off the other VMs slowed down. >>>> >>>> Best Regards >>>> >>>> Michael Schmidt >>>> >>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>>>> Hi Michael, >>>>> >>>>> Thanks for your email. >>>>> >>>>> This is just an idea that I have floating around in my head that >>>>> maybe I''d like to rent out some VPSs to customers, just to utilise my >>>>> machine which will be sitting in a co-lo nearly idle. >>>>> >>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >>>>> >>>>> So the answer is, I don''t know what will be running on them, however >>>>> I could write up an "acceptable use policy", as well as use some >>>>> throttling/scheduling? >>>>> >>>>> Thanks >>>>> >>>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>>>> Hi Jonathan, >>>>>> >>>>>> the question is, what a kind of VM? >>>>>> You can over-utilize a much greater machine with one VM. >>>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>>> >>>>>> Each ressource can be a bottleneck >>>>>> >>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>>> (Reserved for Dom0 should be enugh in this case). >>>>>> - CPU - Here we need a VM statistic >>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>>> cases not the bottleneck >>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>>> botelneck >>>>>> >>>>>> What a kind of VMs you plane to run? >>>>>> Webservers / mailservers / database-servers ...? >>>>>> >>>>>> Best Regards >>>>>> >>>>>> Michael Schmidt >>>>>> >>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>>>> Hi Everyone, >>>>>>> >>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>>> in a RAID1 setup >>>>>>> >>>>>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>>>>> pushing it? >>>>>>> >>>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>>> >>>>>>> Thanks >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Xen-users mailing list >>>>>>> Xen-users@lists.xensource.com >>>>>>> http://lists.xensource.com/xen-users >>>>> _______________________________________________ >>>>> Xen-users mailing list >>>>> Xen-users@lists.xensource.com >>>>> http://lists.xensource.com/xen-users >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users >>> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Software iSCSCI is "free", but all the processing is done by your CPU - the load is not the crucial problem - problem is the speed - with iSCSI offload via the iSCSI HBA you can get significantly better performance (if the software iSCSI is the bottleneck of course) - but it depends on your needs, in many cases software iSCSI is perfectly fine (but there are various implementations - some better, some worse..). iSCSI HBAs (accelerators) are NOT cheap usually. :) The good is, you can bench software iSCSI for "free" (well, the time is not for free :) ) - and it might be perfectly suitable for your application. Important part is to have quality NIC (fast with good offload) and to use network bonds (if not using iSCSI HBAs). Regards Matej ________________________________________ From: xen-users-bounces@lists.xensource.com [xen-users-bounces@lists.xensource.com] On Behalf Of Jonathan Tripathy [jonnyt@abpni.co.uk] Sent: 07 June 2010 09:16 To: Michael Schmidt; Xen-users@lists.xensource.com Subject: Re: [Xen-users] How many guests Hi Michael, You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly free? I agree with you that Fibre Channel systems are very expensive Would iSCSI over IP be ok? Thanks On 07/06/10 08:12, Michael Schmidt wrote:> This is not completely correct. > With a raid 1, you have the read performance of 2 disks and just the > write performance of a single disk. > > To the other thinks following this thread: > If you use a network storage, you have a bandwidth limit with the > connection. But in the most cases, the raw bandwidth is not the > bottleneck (instead of the IOs per second). > > Network Storages using NFS or NBD are not stable enough in my eyes. > iSCSI and FC SANs but really stable and expansive as well. But there > is another much less expensive way: > > You get the most servers with an external SAS port. There you can > connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). > This disks can be managed by the servers raid controller. > > Best Regards > > Michael Schmidt > > > Am 06.06.10 23:21, schrieb Bart Coninckx: >> RAID1 does not perform better than a single disk. It will still >> depend on what >> those 5 to 10 VMs would do. It still might be stretching it. For 10 >> webservers >> visited by 5 users per hour: I would say no problem. For 5 heavily used >> database servers it will be another story. >> >> I guess the only real way to find out is to put your guests on there >> and try. >> If you clone them, you will know quite fast. >> >> >> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: >>> Thanks Micael, >>> >>> I understand what you are saying. >>> >>> With a small setup such as a RAID1 array, how many VMs could I rent >>> out? >>> >>> It doesn''t matter if it''s a small number, it''s just to utilise the >>> server a bit. >>> >>> Think it would cope with 5-10? >>> >>> Thanks >>> >>> Jonathan >>> >>> On 06/06/10 20:18, Michael Schmidt wrote: >>>> Hi Jonathan, >>>> >>>> if you plan to migrate existing physical machines to xen VMs, or you >>>> have some different machines for a comparison, >>>> you can easy get runtime statistics and calculate the usage. Look at >>>> the running iostats and cpu usage. >>>> >>>> If you plan to rent generic VMs on this server to customers, you disk >>>> / raid setup will be absolutely the bottleneck. >>>> A solution at this point is not easy. If you have much write IOs, use >>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>>> same amount of disks. >>>> In each case i can suggest you 15k rpm SAS disks. >>>> >>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>>> >>>> But note: You cannot set disk priority to the VMs. So if one VM does >>>> heavy disk IO, all off the other VMs slowed down. >>>> >>>> Best Regards >>>> >>>> Michael Schmidt >>>> >>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>>>> Hi Michael, >>>>> >>>>> Thanks for your email. >>>>> >>>>> This is just an idea that I have floating around in my head that >>>>> maybe I''d like to rent out some VPSs to customers, just to utilise my >>>>> machine which will be sitting in a co-lo nearly idle. >>>>> >>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >>>>> >>>>> So the answer is, I don''t know what will be running on them, however >>>>> I could write up an "acceptable use policy", as well as use some >>>>> throttling/scheduling? >>>>> >>>>> Thanks >>>>> >>>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>>>> Hi Jonathan, >>>>>> >>>>>> the question is, what a kind of VM? >>>>>> You can over-utilize a much greater machine with one VM. >>>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>>> >>>>>> Each ressource can be a bottleneck >>>>>> >>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>>> (Reserved for Dom0 should be enugh in this case). >>>>>> - CPU - Here we need a VM statistic >>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>>> cases not the bottleneck >>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>>> botelneck >>>>>> >>>>>> What a kind of VMs you plane to run? >>>>>> Webservers / mailservers / database-servers ...? >>>>>> >>>>>> Best Regards >>>>>> >>>>>> Michael Schmidt >>>>>> >>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>>>> Hi Everyone, >>>>>>> >>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>>> in a RAID1 setup >>>>>>> >>>>>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>>>>> pushing it? >>>>>>> >>>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>>> >>>>>>> Thanks >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Xen-users mailing list >>>>>>> Xen-users@lists.xensource.com >>>>>>> http://lists.xensource.com/xen-users >>>>> _______________________________________________ >>>>> Xen-users mailing list >>>>> Xen-users@lists.xensource.com >>>>> http://lists.xensource.com/xen-users >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users >>> >> _______________________________________________ >> Xen-users mailing list >> Xen-users@lists.xensource.com >> http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Jonathan, for iSCSI a iSCSI storage is suggestable, or opene if you plan to run it on a x86 server. But you need dedicated lan line, a storage box with its own raid controller and cpu, memory and so on. And a iSCSI hostbus adapter (around 600€) on the xen host side. If you dont have a iSCSI HBA, you have to use the software iSCSI initiator (i dont like this piece of software, and you have iSCSI CPU Usage on your host). If you want to run just a few more disks for one server (without HA options), you dont need all this overhead. Buy additional to your xen host a SAS Raid controller with an external port (+150€). And a 12-disk JBOD (800€) and the disks (SATA / SAS). This provides you a lower TCO and a higher energy efficiency (3-4U and 450W for 60 VMs). Best Regards Michael Schmidt Am 07.06.10 09:16, schrieb Jonathan Tripathy:> Hi Michael, > > You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly > free? > > I agree with you that Fibre Channel systems are very expensive > > Would iSCSI over IP be ok? > > Thanks > > > On 07/06/10 08:12, Michael Schmidt wrote: >> This is not completely correct. >> With a raid 1, you have the read performance of 2 disks and just the >> write performance of a single disk. >> >> To the other thinks following this thread: >> If you use a network storage, you have a bandwidth limit with the >> connection. But in the most cases, the raw bandwidth is not the >> bottleneck (instead of the IOs per second). >> >> Network Storages using NFS or NBD are not stable enough in my eyes. >> iSCSI and FC SANs but really stable and expansive as well. But there >> is another much less expensive way: >> >> You get the most servers with an external SAS port. There you can >> connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). >> This disks can be managed by the servers raid controller. >> >> Best Regards >> >> Michael Schmidt >> >> >> Am 06.06.10 23:21, schrieb Bart Coninckx: >>> RAID1 does not perform better than a single disk. It will still >>> depend on what >>> those 5 to 10 VMs would do. It still might be stretching it. For 10 >>> webservers >>> visited by 5 users per hour: I would say no problem. For 5 heavily used >>> database servers it will be another story. >>> >>> I guess the only real way to find out is to put your guests on there >>> and try. >>> If you clone them, you will know quite fast. >>> >>> >>> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: >>>> Thanks Micael, >>>> >>>> I understand what you are saying. >>>> >>>> With a small setup such as a RAID1 array, how many VMs could I rent >>>> out? >>>> >>>> It doesn''t matter if it''s a small number, it''s just to utilise the >>>> server a bit. >>>> >>>> Think it would cope with 5-10? >>>> >>>> Thanks >>>> >>>> Jonathan >>>> >>>> On 06/06/10 20:18, Michael Schmidt wrote: >>>>> Hi Jonathan, >>>>> >>>>> if you plan to migrate existing physical machines to xen VMs, or you >>>>> have some different machines for a comparison, >>>>> you can easy get runtime statistics and calculate the usage. Look at >>>>> the running iostats and cpu usage. >>>>> >>>>> If you plan to rent generic VMs on this server to customers, you disk >>>>> / raid setup will be absolutely the bottleneck. >>>>> A solution at this point is not easy. If you have much write IOs, use >>>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>>>> same amount of disks. >>>>> In each case i can suggest you 15k rpm SAS disks. >>>>> >>>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>>>> >>>>> But note: You cannot set disk priority to the VMs. So if one VM does >>>>> heavy disk IO, all off the other VMs slowed down. >>>>> >>>>> Best Regards >>>>> >>>>> Michael Schmidt >>>>> >>>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>>>>> Hi Michael, >>>>>> >>>>>> Thanks for your email. >>>>>> >>>>>> This is just an idea that I have floating around in my head that >>>>>> maybe I''d like to rent out some VPSs to customers, just to >>>>>> utilise my >>>>>> machine which will be sitting in a co-lo nearly idle. >>>>>> >>>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection >>>>>> speed. >>>>>> >>>>>> So the answer is, I don''t know what will be running on them, however >>>>>> I could write up an "acceptable use policy", as well as use some >>>>>> throttling/scheduling? >>>>>> >>>>>> Thanks >>>>>> >>>>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>>>>> Hi Jonathan, >>>>>>> >>>>>>> the question is, what a kind of VM? >>>>>>> You can over-utilize a much greater machine with one VM. >>>>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>>>> >>>>>>> Each ressource can be a bottleneck >>>>>>> >>>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>>>> (Reserved for Dom0 should be enugh in this case). >>>>>>> - CPU - Here we need a VM statistic >>>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>>>> cases not the bottleneck >>>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>>>> botelneck >>>>>>> >>>>>>> What a kind of VMs you plane to run? >>>>>>> Webservers / mailservers / database-servers ...? >>>>>>> >>>>>>> Best Regards >>>>>>> >>>>>>> Michael Schmidt >>>>>>> >>>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>>>>> Hi Everyone, >>>>>>>> >>>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>>>> in a RAID1 setup >>>>>>>> >>>>>>>> How many VMs do you think I''d be able to run on this machine? >>>>>>>> Is 20 >>>>>>>> pushing it? >>>>>>>> >>>>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>>>> >>>>>>>> Thanks >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Xen-users mailing list >>>>>>>> Xen-users@lists.xensource.com >>>>>>>> http://lists.xensource.com/xen-users >>>>>> _______________________________________________ >>>>>> Xen-users mailing list >>>>>> Xen-users@lists.xensource.com >>>>>> http://lists.xensource.com/xen-users >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >>>> >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Michael, Do you have any links to any of those devices you mentioned? Also, would using a software iSCSI initiator defeat the purpose of using RAID10 for performance? Thanks ________________________________ From: Michael Schmidt [mailto:michael.schmidt@xncore.com] Sent: Mon 07/06/2010 08:53 To: Jonathan Tripathy Cc: Xen-users@lists.xensource.com Subject: Re: [Xen-users] How many guests Hi Jonathan, for iSCSI a iSCSI storage is suggestable, or opene if you plan to run it on a x86 server. But you need dedicated lan line, a storage box with its own raid controller and cpu, memory and so on. And a iSCSI hostbus adapter (around 600EUR) on the xen host side. If you dont have a iSCSI HBA, you have to use the software iSCSI initiator (i dont like this piece of software, and you have iSCSI CPU Usage on your host). If you want to run just a few more disks for one server (without HA options), you dont need all this overhead. Buy additional to your xen host a SAS Raid controller with an external port (+150EUR). And a 12-disk JBOD (800EUR) and the disks (SATA / SAS). This provides you a lower TCO and a higher energy efficiency (3-4U and 450W for 60 VMs). Best Regards Michael Schmidt Am 07.06.10 09:16, schrieb Jonathan Tripathy:> Hi Michael, > > You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly > free? > > I agree with you that Fibre Channel systems are very expensive > > Would iSCSI over IP be ok? > > Thanks > > > On 07/06/10 08:12, Michael Schmidt wrote: >> This is not completely correct. >> With a raid 1, you have the read performance of 2 disks and just the >> write performance of a single disk. >> >> To the other thinks following this thread: >> If you use a network storage, you have a bandwidth limit with the >> connection. But in the most cases, the raw bandwidth is not the >> bottleneck (instead of the IOs per second). >> >> Network Storages using NFS or NBD are not stable enough in my eyes. >> iSCSI and FC SANs but really stable and expansive as well. But there >> is another much less expensive way: >> >> You get the most servers with an external SAS port. There you can >> connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). >> This disks can be managed by the servers raid controller. >> >> Best Regards >> >> Michael Schmidt >> >> >> Am 06.06.10 23:21, schrieb Bart Coninckx: >>> RAID1 does not perform better than a single disk. It will still >>> depend on what >>> those 5 to 10 VMs would do. It still might be stretching it. For 10 >>> webservers >>> visited by 5 users per hour: I would say no problem. For 5 heavily used >>> database servers it will be another story. >>> >>> I guess the only real way to find out is to put your guests on there >>> and try. >>> If you clone them, you will know quite fast. >>> >>> >>> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: >>>> Thanks Micael, >>>> >>>> I understand what you are saying. >>>> >>>> With a small setup such as a RAID1 array, how many VMs could I rent >>>> out? >>>> >>>> It doesn''t matter if it''s a small number, it''s just to utilise the >>>> server a bit. >>>> >>>> Think it would cope with 5-10? >>>> >>>> Thanks >>>> >>>> Jonathan >>>> >>>> On 06/06/10 20:18, Michael Schmidt wrote: >>>>> Hi Jonathan, >>>>> >>>>> if you plan to migrate existing physical machines to xen VMs, or you >>>>> have some different machines for a comparison, >>>>> you can easy get runtime statistics and calculate the usage. Look at >>>>> the running iostats and cpu usage. >>>>> >>>>> If you plan to rent generic VMs on this server to customers, you disk >>>>> / raid setup will be absolutely the bottleneck. >>>>> A solution at this point is not easy. If you have much write IOs, use >>>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>>>> same amount of disks. >>>>> In each case i can suggest you 15k rpm SAS disks. >>>>> >>>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>>>> >>>>> But note: You cannot set disk priority to the VMs. So if one VM does >>>>> heavy disk IO, all off the other VMs slowed down. >>>>> >>>>> Best Regards >>>>> >>>>> Michael Schmidt >>>>> >>>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>>>>> Hi Michael, >>>>>> >>>>>> Thanks for your email. >>>>>> >>>>>> This is just an idea that I have floating around in my head that >>>>>> maybe I''d like to rent out some VPSs to customers, just to >>>>>> utilise my >>>>>> machine which will be sitting in a co-lo nearly idle. >>>>>> >>>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection >>>>>> speed. >>>>>> >>>>>> So the answer is, I don''t know what will be running on them, however >>>>>> I could write up an "acceptable use policy", as well as use some >>>>>> throttling/scheduling? >>>>>> >>>>>> Thanks >>>>>> >>>>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>>>>> Hi Jonathan, >>>>>>> >>>>>>> the question is, what a kind of VM? >>>>>>> You can over-utilize a much greater machine with one VM. >>>>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>>>> >>>>>>> Each ressource can be a bottleneck >>>>>>> >>>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>>>> (Reserved for Dom0 should be enugh in this case). >>>>>>> - CPU - Here we need a VM statistic >>>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>>>> cases not the bottleneck >>>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>>>> botelneck >>>>>>> >>>>>>> What a kind of VMs you plane to run? >>>>>>> Webservers / mailservers / database-servers ...? >>>>>>> >>>>>>> Best Regards >>>>>>> >>>>>>> Michael Schmidt >>>>>>> >>>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>>>>> Hi Everyone, >>>>>>>> >>>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>>>> in a RAID1 setup >>>>>>>> >>>>>>>> How many VMs do you think I''d be able to run on this machine? >>>>>>>> Is 20 >>>>>>>> pushing it? >>>>>>>> >>>>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>>>> >>>>>>>> Thanks >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Xen-users mailing list >>>>>>>> Xen-users@lists.xensource.com >>>>>>>> http://lists.xensource.com/xen-users >>>>>> _______________________________________________ >>>>>> Xen-users mailing list >>>>>> Xen-users@lists.xensource.com >>>>>> http://lists.xensource.com/xen-users >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >>>> >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Note, that dell r210 comes with broadcom netxtreme II NICs, wo have a iSCSI offload engine. But i guess its not supported by the linux drivers / os. A full qualified iSCSI HBA is absolutly suggestable. But this leads to think about much faster and stabler FC. Best Regards Michael Schmidt Am 07.06.10 09:39, schrieb Matej Zary:> Software iSCSCI is "free", but all the processing is done by your CPU - the load is not the crucial problem - problem is the speed - with iSCSI offload via the iSCSI HBA you can get significantly better performance (if the software iSCSI is the bottleneck of course) - but it depends on your needs, in many cases software iSCSI is perfectly fine (but there are various implementations - some better, some worse..). iSCSI HBAs (accelerators) are NOT cheap usually. :) > > > The good is, you can bench software iSCSI for "free" (well, the time is not for free :) ) - and it might be perfectly suitable for your application. > Important part is to have quality NIC (fast with good offload) and to use network bonds (if not using iSCSI HBAs). > > > > Regards > > > Matej > > > > ________________________________________ > From: xen-users-bounces@lists.xensource.com [xen-users-bounces@lists.xensource.com] On Behalf Of Jonathan Tripathy [jonnyt@abpni.co.uk] > Sent: 07 June 2010 09:16 > To: Michael Schmidt; Xen-users@lists.xensource.com > Subject: Re: [Xen-users] How many guests > > Hi Michael, > > You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly free? > > I agree with you that Fibre Channel systems are very expensive > > Would iSCSI over IP be ok? > > Thanks > > > On 07/06/10 08:12, Michael Schmidt wrote: > >> This is not completely correct. >> With a raid 1, you have the read performance of 2 disks and just the >> write performance of a single disk. >> >> To the other thinks following this thread: >> If you use a network storage, you have a bandwidth limit with the >> connection. But in the most cases, the raw bandwidth is not the >> bottleneck (instead of the IOs per second). >> >> Network Storages using NFS or NBD are not stable enough in my eyes. >> iSCSI and FC SANs but really stable and expansive as well. But there >> is another much less expensive way: >> >> You get the most servers with an external SAS port. There you can >> connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). >> This disks can be managed by the servers raid controller. >> >> Best Regards >> >> Michael Schmidt >> >> >> Am 06.06.10 23:21, schrieb Bart Coninckx: >> >>> RAID1 does not perform better than a single disk. It will still >>> depend on what >>> those 5 to 10 VMs would do. It still might be stretching it. For 10 >>> webservers >>> visited by 5 users per hour: I would say no problem. For 5 heavily used >>> database servers it will be another story. >>> >>> I guess the only real way to find out is to put your guests on there >>> and try. >>> If you clone them, you will know quite fast. >>> >>> >>> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: >>> >>>> Thanks Micael, >>>> >>>> I understand what you are saying. >>>> >>>> With a small setup such as a RAID1 array, how many VMs could I rent >>>> out? >>>> >>>> It doesn''t matter if it''s a small number, it''s just to utilise the >>>> server a bit. >>>> >>>> Think it would cope with 5-10? >>>> >>>> Thanks >>>> >>>> Jonathan >>>> >>>> On 06/06/10 20:18, Michael Schmidt wrote: >>>> >>>>> Hi Jonathan, >>>>> >>>>> if you plan to migrate existing physical machines to xen VMs, or you >>>>> have some different machines for a comparison, >>>>> you can easy get runtime statistics and calculate the usage. Look at >>>>> the running iostats and cpu usage. >>>>> >>>>> If you plan to rent generic VMs on this server to customers, you disk >>>>> / raid setup will be absolutely the bottleneck. >>>>> A solution at this point is not easy. If you have much write IOs, use >>>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the >>>>> same amount of disks. >>>>> In each case i can suggest you 15k rpm SAS disks. >>>>> >>>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. >>>>> >>>>> But note: You cannot set disk priority to the VMs. So if one VM does >>>>> heavy disk IO, all off the other VMs slowed down. >>>>> >>>>> Best Regards >>>>> >>>>> Michael Schmidt >>>>> >>>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: >>>>> >>>>>> Hi Michael, >>>>>> >>>>>> Thanks for your email. >>>>>> >>>>>> This is just an idea that I have floating around in my head that >>>>>> maybe I''d like to rent out some VPSs to customers, just to utilise my >>>>>> machine which will be sitting in a co-lo nearly idle. >>>>>> >>>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection speed. >>>>>> >>>>>> So the answer is, I don''t know what will be running on them, however >>>>>> I could write up an "acceptable use policy", as well as use some >>>>>> throttling/scheduling? >>>>>> >>>>>> Thanks >>>>>> >>>>>> On 06/06/10 19:39, Michael Schmidt wrote: >>>>>> >>>>>>> Hi Jonathan, >>>>>>> >>>>>>> the question is, what a kind of VM? >>>>>>> You can over-utilize a much greater machine with one VM. >>>>>>> Or on the other side, you can run 40 VMs on a shorter machine. >>>>>>> >>>>>>> Each ressource can be a bottleneck >>>>>>> >>>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB >>>>>>> (Reserved for Dom0 should be enugh in this case). >>>>>>> - CPU - Here we need a VM statistic >>>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most >>>>>>> cases not the bottleneck >>>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the >>>>>>> botelneck >>>>>>> >>>>>>> What a kind of VMs you plane to run? >>>>>>> Webservers / mailservers / database-servers ...? >>>>>>> >>>>>>> Best Regards >>>>>>> >>>>>>> Michael Schmidt >>>>>>> >>>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: >>>>>>> >>>>>>>> Hi Everyone, >>>>>>>> >>>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU >>>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller >>>>>>>> in a RAID1 setup >>>>>>>> >>>>>>>> How many VMs do you think I''d be able to run on this machine? Is 20 >>>>>>>> pushing it? >>>>>>>> >>>>>>>> I''d say most (if not all) guests would be in PV mode. >>>>>>>> >>>>>>>> Thanks >>>>>>>> >>>>>>>> _______________________________________________ >>>>>>>> Xen-users mailing list >>>>>>>> Xen-users@lists.xensource.com >>>>>>>> http://lists.xensource.com/xen-users >>>>>>>> >>>>>> _______________________________________________ >>>>>> Xen-users mailing list >>>>>> Xen-users@lists.xensource.com >>>>>> http://lists.xensource.com/xen-users >>>>>> >>>> _______________________________________________ >>>> Xen-users mailing list >>>> Xen-users@lists.xensource.com >>>> http://lists.xensource.com/xen-users >>>> >>>> >>> _______________________________________________ >>> Xen-users mailing list >>> Xen-users@lists.xensource.com >>> http://lists.xensource.com/xen-users >>> > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Jonathan, nearly each storage manufacturer has JBODs with SAS expander for their storages. You can use this all. Which manufacturer is not important - because it is a nearly passive component. So you can use a cheap one like Infortrend or Promise. http://www.infortrend.com/main/2_product/es_s16s-j1000-rs.asp ( S16S-J1000-S) On a iSCSI storage, you can export each block device as iSCSI target. On the xen host side, you just connect this exported iSCSI block device with the initiator. Best Regards Michael Schmidt Am 07.06.10 10:45, schrieb Jonathan Tripathy:> Hi Michael, > Do you have any links to any of those devices you mentioned? > Also, would using a software iSCSI initiator defeat the purpose of > using RAID10 for performance? > Thanks > > ------------------------------------------------------------------------ > *From:* Michael Schmidt [mailto:michael.schmidt@xncore.com] > *Sent:* Mon 07/06/2010 08:53 > *To:* Jonathan Tripathy > *Cc:* Xen-users@lists.xensource.com > *Subject:* Re: [Xen-users] How many guests > > Hi Jonathan, > > for iSCSI a iSCSI storage is suggestable, or opene if you plan to run it > on a x86 server. > But you need dedicated lan line, a storage box with its own raid > controller and cpu, memory and so on. > And a iSCSI hostbus adapter (around 600EUR) on the xen host side. If you > dont have a iSCSI HBA, you have to use the > software iSCSI initiator (i dont like this piece of software, and you > have iSCSI CPU Usage on your host). > > If you want to run just a few more disks for one server (without HA > options), you dont need all this overhead. > Buy additional to your xen host a SAS Raid controller with an external > port (+150EUR). And a 12-disk JBOD (800EUR) and the disks (SATA / SAS). > > This provides you a lower TCO and a higher energy efficiency (3-4U and > 450W for 60 VMs). > > Best Regards > > Michael Schmidt > > > Am 07.06.10 09:16, schrieb Jonathan Tripathy: > > Hi Michael, > > > > You state that iSCSI is reliable but expensive. But isn''t iSCSI nearly > > free? > > > > I agree with you that Fibre Channel systems are very expensive > > > > Would iSCSI over IP be ok? > > > > Thanks > > > > > > On 07/06/10 08:12, Michael Schmidt wrote: > >> This is not completely correct. > >> With a raid 1, you have the read performance of 2 disks and just the > >> write performance of a single disk. > >> > >> To the other thinks following this thread: > >> If you use a network storage, you have a bandwidth limit with the > >> connection. But in the most cases, the raw bandwidth is not the > >> bottleneck (instead of the IOs per second). > >> > >> Network Storages using NFS or NBD are not stable enough in my eyes. > >> iSCSI and FC SANs but really stable and expansive as well. But there > >> is another much less expensive way: > >> > >> You get the most servers with an external SAS port. There you can > >> connect over a SAS link a JBOD with 12 - 16 disk bays (DAS). > >> This disks can be managed by the servers raid controller. > >> > >> Best Regards > >> > >> Michael Schmidt > >> > >> > >> Am 06.06.10 23:21, schrieb Bart Coninckx: > >>> RAID1 does not perform better than a single disk. It will still > >>> depend on what > >>> those 5 to 10 VMs would do. It still might be stretching it. For 10 > >>> webservers > >>> visited by 5 users per hour: I would say no problem. For 5 heavily > used > >>> database servers it will be another story. > >>> > >>> I guess the only real way to find out is to put your guests on there > >>> and try. > >>> If you clone them, you will know quite fast. > >>> > >>> > >>> On Sunday 06 June 2010 21:38:54 Jonathan Tripathy wrote: > >>>> Thanks Micael, > >>>> > >>>> I understand what you are saying. > >>>> > >>>> With a small setup such as a RAID1 array, how many VMs could I rent > >>>> out? > >>>> > >>>> It doesn''t matter if it''s a small number, it''s just to utilise the > >>>> server a bit. > >>>> > >>>> Think it would cope with 5-10? > >>>> > >>>> Thanks > >>>> > >>>> Jonathan > >>>> > >>>> On 06/06/10 20:18, Michael Schmidt wrote: > >>>>> Hi Jonathan, > >>>>> > >>>>> if you plan to migrate existing physical machines to xen VMs, or you > >>>>> have some different machines for a comparison, > >>>>> you can easy get runtime statistics and calculate the usage. Look at > >>>>> the running iostats and cpu usage. > >>>>> > >>>>> If you plan to rent generic VMs on this server to customers, you > disk > >>>>> / raid setup will be absolutely the bottleneck. > >>>>> A solution at this point is not easy. If you have much write > IOs, use > >>>>> raid 10 with 4 to 8 disks. With many reads - raid 6 or 50 with the > >>>>> same amount of disks. > >>>>> In each case i can suggest you 15k rpm SAS disks. > >>>>> > >>>>> Then you can run 29 VMs. Or 60 VMs with 16GB memory and 2 CPUs. > >>>>> > >>>>> But note: You cannot set disk priority to the VMs. So if one VM does > >>>>> heavy disk IO, all off the other VMs slowed down. > >>>>> > >>>>> Best Regards > >>>>> > >>>>> Michael Schmidt > >>>>> > >>>>> Am 06.06.10 20:45, schrieb Jonathan Tripathy: > >>>>>> Hi Michael, > >>>>>> > >>>>>> Thanks for your email. > >>>>>> > >>>>>> This is just an idea that I have floating around in my head that > >>>>>> maybe I''d like to rent out some VPSs to customers, just to > >>>>>> utilise my > >>>>>> machine which will be sitting in a co-lo nearly idle. > >>>>>> > >>>>>> I''d give out VPSs with 256MB RAM and probably 5Mbps connection > >>>>>> speed. > >>>>>> > >>>>>> So the answer is, I don''t know what will be running on them, > however > >>>>>> I could write up an "acceptable use policy", as well as use some > >>>>>> throttling/scheduling? > >>>>>> > >>>>>> Thanks > >>>>>> > >>>>>> On 06/06/10 19:39, Michael Schmidt wrote: > >>>>>>> Hi Jonathan, > >>>>>>> > >>>>>>> the question is, what a kind of VM? > >>>>>>> You can over-utilize a much greater machine with one VM. > >>>>>>> Or on the other side, you can run 40 VMs on a shorter machine. > >>>>>>> > >>>>>>> Each ressource can be a bottleneck > >>>>>>> > >>>>>>> - Memory - this is realy easy to calculate: Avaiable minus 768MB > >>>>>>> (Reserved for Dom0 should be enugh in this case). > >>>>>>> - CPU - Here we need a VM statistic > >>>>>>> - Disk Bandwidth - Here we need a VM statistic, but in the most > >>>>>>> cases not the bottleneck > >>>>>>> - Disk IOPS - Here we need a VM statistic, in the most cases the > >>>>>>> botelneck > >>>>>>> > >>>>>>> What a kind of VMs you plane to run? > >>>>>>> Webservers / mailservers / database-servers ...? > >>>>>>> > >>>>>>> Best Regards > >>>>>>> > >>>>>>> Michael Schmidt > >>>>>>> > >>>>>>> Am 06.06.10 00:54, schrieb Jonathan Tripathy: > >>>>>>>> Hi Everyone, > >>>>>>>> > >>>>>>>> I have a Dell R210 server which has a Xeon X3430 Quad Core CPU > >>>>>>>> (2.4Ghz x 4) with 8GB of RAM. I intend to use the H200 controller > >>>>>>>> in a RAID1 setup > >>>>>>>> > >>>>>>>> How many VMs do you think I''d be able to run on this machine? > >>>>>>>> Is 20 > >>>>>>>> pushing it? > >>>>>>>> > >>>>>>>> I''d say most (if not all) guests would be in PV mode. > >>>>>>>> > >>>>>>>> Thanks > >>>>>>>> > >>>>>>>> _______________________________________________ > >>>>>>>> Xen-users mailing list > >>>>>>>> Xen-users@lists.xensource.com > >>>>>>>> http://lists.xensource.com/xen-users > >>>>>> _______________________________________________ > >>>>>> Xen-users mailing list > >>>>>> Xen-users@lists.xensource.com > >>>>>> http://lists.xensource.com/xen-users > >>>> _______________________________________________ > >>>> Xen-users mailing list > >>>> Xen-users@lists.xensource.com > >>>> http://lists.xensource.com/xen-users > >>>> > >>> _______________________________________________ > >>> Xen-users mailing list > >>> Xen-users@lists.xensource.com > >>> http://lists.xensource.com/xen-users > > > > _______________________________________________ > > Xen-users mailing list > > Xen-users@lists.xensource.com > > http://lists.xensource.com/xen-users > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users