Angel L. Mateo
2010-Feb-09 13:43 UTC
[Xen-users] LVM snapshots to provide HA iSCSI storage
Hello, This is not a properly Xen problem, but I guess somebody has set out this same configuration, so I think you could help me. So sorry if you this is an offtopic message. We are planning to migrate our locally storaged VM (in LVM volumes) to a central storage, so we could you live migration and to provide HA mechanisms to our VM. For the central storage, we are planning to use iSCSI with LVM over it. The problem with this configuration is that if your iSCSI server (the target) fails, then all your VMs fail, and this a problem for us. So what we have thought is to use LVM to mirror our volumes. The idea is that the disk for a VM is in a iSCSI LVM volume: * When we start a VM, then we create a mirror using the the iSCSI LVM and another volume in a local disk, then the VM uses this mirror. * If the iSCSI server goes down, there is no problem, because we have the local volume (when it goes up again, the mirror will synchronize the contents). * When we stop the VM, then we destroy the mirror and store the iSCSI volume. * When the migration, we destroy the mirror in the dom0 and create it in the other dom0. Running this scripts is not a problem, because we are going to use opennebule, where we can personalize the actions taking place in these situations. Is this posible? Does anybody use this idea (or similar)? Could anybody point me to some documentation? -- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información _o) y las Comunicaciones Aplicadas (ATICA) / \\ http://www.um.es/atica _(___V Tfo: 868887590 Fax: 868888337 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
<macscr@macscr.com>
2010-Feb-09 15:47 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
In case you didnt know, clvm doesnt support snapshots. On Tue, 09 Feb 2010 14:43:24 +0100, "Angel L. Mateo" <amateo@um.es> wrote:> Hello, > > This is not a properly Xen problem, but I guess somebody has set out > this same configuration, so I think you could help me. So sorry if you > this is an offtopic message. > > We are planning to migrate our locally storaged VM (in LVM volumes) to > a central storage, so we could you live migration and to provide HA > mechanisms to our VM. For the central storage, we are planning to use > iSCSI with LVM over it. > > The problem with this configuration is that if your iSCSI server (the > target) fails, then all your VMs fail, and this a problem for us. > > So what we have thought is to use LVM to mirror our volumes. The idea > is that the disk for a VM is in a iSCSI LVM volume: > > * When we start a VM, then we create a mirror using the the iSCSI LVM > and another volume in a local disk, then the VM uses this mirror. > * If the iSCSI server goes down, there is no problem, because we have > the local volume (when it goes up again, the mirror will synchronize the > contents). > * When we stop the VM, then we destroy the mirror and store the iSCSI > volume. > * When the migration, we destroy the mirror in the dom0 and create it in > the other dom0. > > Running this scripts is not a problem, because we are going to use > opennebule, where we can personalize the actions taking place in these > situations. > > Is this posible? Does anybody use this idea (or similar)? Could anybody > point me to some documentation?_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
John Madden
2010-Feb-09 16:12 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
> Is this posible? Does anybody use this idea (or similar)? Could anybody > point me to some documentation?I''ve done this with md mirroring instead of lvm but I haven''t gotten to the live migration part. You create and manage the md on dom0 and give that to the domU via phy: mappings. The way I see it, you''d have to break the mirror during migration (or keep it broken on the inactive dom0) and then re-sync it on the new-active node during migration. But yeah, given clvm on iSCSI and some fancy migration scripting, I don''t see why this wouldn''t work. John -- John Madden Sr UNIX Systems Engineer Ivy Tech Community College of Indiana jmadden@ivytech.edu _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, I''m new in virtualization technologies and have found Citrix Xen Server seems to provide a free GUI tool for administration of Virtual Machines, etc. based on Xen. Is Citrix Xen Server the best way to start trying xen ? what limitations has the "Free" licence ? Regards, Fernando _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> I'm new in virtualization technologies and have found Citrix Xen Server > seems to provide a free GUI tool for administration of Virtual Machines, > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen >? what limitations has the "Free" licence ?> Regards, > FernandoFernando, Citrix XenServer is a product built upon the open source Xen platform. The Open Source community now supports a complete build image downloadable in iso format to try called Xen Cloud Platform. It does not have the free GUI tool built-in but there are several options already available to manage XCP - see http://www.xen.org/products/cloud_projects.html. Thanks. Stephen Spector _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi! I believe that the best place to ask about the Citrix XenServer is at the Citrix Foruns... Because this list is intended only for the open source version of the Xen... Someone correct me if I''m wrong! Regards, Thiago On 9 February 2010 14:33, Fernando Berretta <fernando.berretta@gmail.com>wrote:> Hi, > > I''m new in virtualization technologies and have found Citrix Xen Server > seems to provide a free GUI tool for administration of Virtual Machines, > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen ? > what limitations has the "Free" licence ? > > Regards, > Fernando > > _______________________________________________ > 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
Stephen, The XenServer will have new versions? I mean, the Citrix company will release a XenServer 6, for example? Or the XenServer 5.5 will be the last one and the XCP is the future?! Thanks! Thiago On 9 February 2010 16:08, Stephen Spector <stephen.spector@citrix.com>wrote:> > > I''m new in virtualization technologies and have found Citrix Xen Server > > seems to provide a free GUI tool for administration of Virtual Machines, > > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen > >? what limitations has the "Free" licence ? > > > Regards, > > Fernando > > Fernando, > Citrix XenServer is a product built upon the open source Xen platform. The > Open Source community now supports a complete build image downloadable in > iso format to try called Xen Cloud Platform. It does not have the free GUI > tool built-in but there are several options already available to manage XCP > - see http://www.xen.org/products/cloud_projects.html. > > Thanks. > > Stephen Spector > > _______________________________________________ > 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
No, Citrix will continue to act independently from Xen.org on XenServer as it is their primary solution. They plan to leverage XCP (as anyone else can) to place new features and ideas into the community for trial and experimentation. They will then pull what they see as the best fit for their customers into XenServer. Thanks. From: Thiago Camargo Martins Cordeiro [mailto:thiagocmartinsc@gmail.com] Sent: Tuesday, February 09, 2010 1:14 PM To: Stephen Spector Cc: Fernando Berretta; xen-users@lists.xensource.com Subject: Re: [Xen-users] Citrix Xen Server Stephen, The XenServer will have new versions? I mean, the Citrix company will release a XenServer 6, for example? Or the XenServer 5.5 will be the last one and the XCP is the future?! Thanks! Thiago On 9 February 2010 16:08, Stephen Spector <stephen.spector@citrix.com<mailto:stephen.spector@citrix.com>> wrote:> I''m new in virtualization technologies and have found Citrix Xen Server > seems to provide a free GUI tool for administration of Virtual Machines, > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen >? what limitations has the "Free" licence ?> Regards, > FernandoFernando, Citrix XenServer is a product built upon the open source Xen platform. The Open Source community now supports a complete build image downloadable in iso format to try called Xen Cloud Platform. It does not have the free GUI tool built-in but there are several options already available to manage XCP - see http://www.xen.org/products/cloud_projects.html. Thanks. Stephen Spector _______________________________________________ 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
Thanks Stephen! Good to know this stuff! Can we organize some page to compare the XenServer and XCP and what stuff can be/should be included in the XenServer from the XCP? On 9 February 2010 16:23, Stephen Spector <stephen.spector@citrix.com>wrote:> No, Citrix will continue to act independently from Xen.org on XenServer > as it is their primary solution. They plan to leverage XCP (as anyone else > can) to place new features and ideas into the community for trial and > experimentation. They will then pull what they see as the best fit for their > customers into XenServer. > > > > Thanks. > > > > *From:* Thiago Camargo Martins Cordeiro [mailto:thiagocmartinsc@gmail.com] > > *Sent:* Tuesday, February 09, 2010 1:14 PM > *To:* Stephen Spector > *Cc:* Fernando Berretta; xen-users@lists.xensource.com > *Subject:* Re: [Xen-users] Citrix Xen Server > > > > Stephen, > > The XenServer will have new versions? I mean, the Citrix company will > release a XenServer 6, for example? Or the XenServer 5.5 will be the last > one and the XCP is the future?! > > Thanks! > Thiago > > On 9 February 2010 16:08, Stephen Spector <stephen.spector@citrix.com> > wrote: > > > > I''m new in virtualization technologies and have found Citrix Xen Server > > seems to provide a free GUI tool for administration of Virtual Machines, > > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen > >? what limitations has the "Free" licence ? > > > Regards, > > Fernando > > Fernando, > Citrix XenServer is a product built upon the open source Xen platform. The > Open Source community now supports a complete build image downloadable in > iso format to try called Xen Cloud Platform. It does not have the free GUI > tool built-in but there are several options already available to manage XCP > - see http://www.xen.org/products/cloud_projects.html. > > Thanks. > > Stephen Spector > > _______________________________________________ > 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, Just curious, whats the difference between the citrix xenserver and the xen opensource cloud? I don’t understand why there are different versions of it. Thanks Ian -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Stephen Spector Sent: 09 February 2010 18:09 To: 'Fernando Berretta'; xen-users@lists.xensource.com Subject: RE: [Xen-users] Citrix Xen Server> I'm new in virtualization technologies and have found Citrix Xen >Server seems to provide a free GUI tool for administration of Virtual >Machines, etc. based on Xen. Is Citrix Xen Server the best way to >start trying xen ? what limitations has the "Free" licence ?> Regards, > FernandoFernando, Citrix XenServer is a product built upon the open source Xen platform. The Open Source community now supports a complete build image downloadable in iso format to try called Xen Cloud Platform. It does not have the free GUI tool built-in but there are several options already available to manage XCP - see http://www.xen.org/products/cloud_projects.html. Thanks. Stephen Spector _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi,> Just curious, whats the difference between the citrix xenserver and the > xen opensource cloud? I don’t understand why there are different > versions of it.Xen Cloud Platform is all open-source (except the windows PV drivers), collaboratively developed and suitable for exposing/trying out new "experimental" features (e.g. basic SRIOV support) Citrix XenServer is a commercial product based on the same open-source bits but with some non-OSS stuff on top (e.g. Windows console, HA, Workload Balancing) New features currently in the Xen Cloud Platform (e.g. dynamic memory control; role-based admin; live checkpoint) will end up in XenServer, since they are both based on the same code. Therefore if you want to try out the latest bleeding-edge stuff, you should probably try XCP.. Dave> > Thanks > > Ian > > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] On Behalf Of Stephen Spector > Sent: 09 February 2010 18:09 > To: 'Fernando Berretta'; xen-users@lists.xensource.com > Subject: RE: [Xen-users] Citrix Xen Server > > > > I'm new in virtualization technologies and have found Citrix Xen > >Server seems to provide a free GUI tool for administration of Virtual > >Machines, etc. based on Xen. Is Citrix Xen Server the best way to > >start trying xen ? what limitations has the "Free" licence ? > > > Regards, > > Fernando > > Fernando, > Citrix XenServer is a product built upon the open source Xen platform. > The Open Source community now supports a complete build image > downloadable in iso format to try called Xen Cloud Platform. It does > not have the free GUI tool built-in but there are several options > already available to manage XCP - see > http://www.xen.org/products/cloud_projects.html. > > Thanks. > > Stephen Spector_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Stephen Spector wrote:>> I''m new in virtualization technologies and have found Citrix Xen Server >> seems to provide a free GUI tool for administration of Virtual Machines, >> etc. based on Xen. Is Citrix Xen Server the best way to start trying xen >> ? what limitations has the "Free" licence ? >> > > >> Regards, >> Fernando >> > > Fernando, > Citrix XenServer is a product built upon the open source Xen platform. The Open Source community now supports a complete build image downloadable in iso format to try called Xen Cloud Platform. It does not have the free GUI tool built-in but there are several options already available to manage XCP - see http://www.xen.org/products/cloud_projects.html. > > Thanks. > > Stephen Spector >Stephen, Thanks for information and link provided. I''m gonna check it But.. I''ve seen some ISPs are offering hosted dedicated servers with Citrix Xenserver preinstalled at no charge so.. it is very interesting at least for me. Do you think next XenServer releases are going to continue being "free" and based on open source xen and not in a branch of it Best Regards, Fernando _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks for clearing that up :) Ian -----Original Message----- From: Dave Scott [mailto:Dave.Scott@eu.citrix.com] Sent: 09 February 2010 21:24 To: Ian Tobin; Stephen Spector; Fernando Berretta; xen-users@lists.xensource.com Subject: RE: [Xen-users] Citrix Xen Server Hi,> Just curious, whats the difference between the citrix xenserver and the > xen opensource cloud? I don’t understand why there are different > versions of it.Xen Cloud Platform is all open-source (except the windows PV drivers), collaboratively developed and suitable for exposing/trying out new "experimental" features (e.g. basic SRIOV support) Citrix XenServer is a commercial product based on the same open-source bits but with some non-OSS stuff on top (e.g. Windows console, HA, Workload Balancing) New features currently in the Xen Cloud Platform (e.g. dynamic memory control; role-based admin; live checkpoint) will end up in XenServer, since they are both based on the same code. Therefore if you want to try out the latest bleeding-edge stuff, you should probably try XCP.. Dave> > Thanks > > Ian > > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto:xen-users- > bounces@lists.xensource.com] On Behalf Of Stephen Spector > Sent: 09 February 2010 18:09 > To: 'Fernando Berretta'; xen-users@lists.xensource.com > Subject: RE: [Xen-users] Citrix Xen Server > > > > I'm new in virtualization technologies and have found Citrix Xen > >Server seems to provide a free GUI tool for administration of Virtual > >Machines, etc. based on Xen. Is Citrix Xen Server the best way to > >start trying xen ? what limitations has the "Free" licence ? > > > Regards, > > Fernando > > Fernando, > Citrix XenServer is a product built upon the open source Xen platform. > The Open Source community now supports a complete build image > downloadable in iso format to try called Xen Cloud Platform. It does > not have the free GUI tool built-in but there are several options > already available to manage XCP - see > http://www.xen.org/products/cloud_projects.html. > > Thanks. > > Stephen Spector_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2010-Feb-09 23:49 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
On Tue, Feb 9, 2010 at 8:43 PM, Angel L. Mateo <amateo@um.es> wrote:> * If the iSCSI server goes down, there is no problem, because we have > the local volume (when it goes up again, the mirror will synchronize the > contents).That will be the tricky part. First you need to find a balance between iscsi retry/timeout. IIRC default set to unlimited, which means if iscsi server is dead, dom0 will wait forever for it to come back up, making your local copy useless. Then you need some way of telling LVM "the iscsi server has come back up, resync". Let us know if you found a working solution. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Angel L. Mateo
2010-Feb-10 08:25 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
El mar, 09-02-2010 a las 11:12 -0500, John Madden escribió:> > Is this posible? Does anybody use this idea (or similar)? Could anybody > > point me to some documentation? > > I''ve done this with md mirroring instead of lvm but I haven''t gotten to > the live migration part. You create and manage the md on dom0 and give > that to the domU via phy: mappings. >Do you have any documentation of this? I could be interested. I am trying to do it with lvm volumes and dmsetup, but I am getting problems when the iscsi connection fails. -- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información _o) y las Comunicaciones Aplicadas (ATICA) / \\ http://www.um.es/atica _(___V Tfo: 868887590 Fax: 868888337 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Angel L. Mateo
2010-Feb-10 08:26 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
El mar, 09-02-2010 a las 11:12 -0500, John Madden escribió:> > Is this posible? Does anybody use this idea (or similar)? Could anybody > > point me to some documentation? > > I''ve done this with md mirroring instead of lvm but I haven''t gotten to > the live migration part. You create and manage the md on dom0 and give > that to the domU via phy: mappings. >Do you have any documentation of this? I could be interested. I am trying to do it with lvm volumes and dmsetup, but I am getting problems when the iscsi connection fails. -- Angel L. Mateo Martínez Sección de Telemática Área de Tecnologías de la Información _o) y las Comunicaciones Aplicadas (ATICA) / \\ http://www.um.es/atica _(___V Tfo: 868887590 Fax: 868888337 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
John Madden
2010-Feb-10 15:14 UTC
Re: [Xen-users] LVM snapshots to provide HA iSCSI storage
>> I''ve done this with md mirroring instead of lvm but I haven''t gotten to >> the live migration part. You create and manage the md on dom0 and give >> that to the domU via phy: mappings. >> > Do you have any documentation of this? I could be interested. I am > trying to do it with lvm volumes and dmsetup, but I am getting problems > when the iscsi connection fails.Not really. It''s a standard scsi disk, so you create a VG, put the disk in it, create an LV, and then use mdadm to create the mirror with your local disk. When iSCSI fails, it should fail the same way a SCSI disk would fail if you pulled the cable out of it. My targets are all ietd, so I just turned the service off to test. John -- John Madden Sr UNIX Systems Engineer Ivy Tech Community College of Indiana jmadden@ivytech.edu _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Tue, 2010-02-09 at 13:33 -0300, Fernando Berretta wrote:> Hi, > > I''m new in virtualization technologies and have found Citrix Xen Server > seems to provide a free GUI tool for administration of Virtual Machines, > etc. based on Xen. Is Citrix Xen Server the best way to start trying xen > ? what limitations has the "Free" licence ? >Hi Fernando. We''ve been running SLES10/SLES11 xen servers for quite some time. We use ocfs2 for our storage. I''ve always had some nagging issues with memory, but the last two weeks I''ve had some major outages and problems. I have a couple tickets open with Novell right now. I think my issues are mostly ocfs2 related. In the mean time I decided to try XenServer. At first it looks really great. The management gui is excellent, and easy to use. Once you have their xs-tools installed it extremely easy to moving a VM to another host without shutting it down. I have yet to get this working on my servers. The major drawbacks I''ve come across this week compared to what we do now on sles are: -setting up a suse linux paravirtualized machine seems like major pain. converting my current sles VMs seems impossible, or at best very difficult. -we use a Xiotech SAN and although you can setup shared storage, you cannot use sparse files, so your storage requirements are a lot higher. As far as I can tell, the only way to use sparse files on XenServer is by using NFS. -I feel like I lose a lot of flexibility, especially with linux VMs. on my current servers I can mount the disk files and access the files in them if needed. I can easily copy a disk file and then create a new VM based on that file. On XenServer I have copied a Windows VM and created another one, but I haven''t figured out how to take a disk and create a VM using that existing virtual disk. -getting help on the citrix forum is very hit and miss. you''re lucky to get an answer very quickly as opposed to here where you typically get some kind of answer within hours, if not sooner. It could be that I''m just missing some important aspects of XenServer that I have yet to figure out. You should try it and see if it fits for you. Now, back to my problems.... James _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
James, Thanks for your detailed response. Comments inline. Regards,> Hi Fernando. We''ve been running SLES10/SLES11 xen servers for quite some > time. We use ocfs2 for our storage. I''ve always had some nagging issues > with memory, but the last two weeks I''ve had some major outages and > problems. I have a couple tickets open with Novell right now. I think my > issues are mostly ocfs2 related. > > In the mean time I decided to try XenServer. At first it looks really > great. The management gui is excellent, and easy to use. Once you have > their xs-tools installed it extremely easy to moving a VM to another > host without shutting it down. I have yet to get this working on my > servers. > > The major drawbacks I''ve come across this week compared to what we do > now on sles are: > > -setting up a suse linux paravirtualized machine seems like major pain. > converting my current sles VMs seems impossible, or at best very > difficult. > > -we use a Xiotech SAN and although you can setup shared storage, you > cannot use sparse files, so your storage requirements are a lot higher. > As far as I can tell, the only way to use sparse files on XenServer is > by using NFS. > > -I feel like I lose a lot of flexibility, especially with linux VMs. on > my current servers I can mount the disk files and access the files in > them if needed. I can easily copy a disk file and then create a new VM > based on that file. On XenServer I have copied a Windows VM and created > another one, but I haven''t figured out how to take a disk and create a > VM using that existing virtual disk. >based on your comments, Seems like simplicity provided by Citrix GUI is against flexibility provided by XEN, is very important for me also to be able to clone machines based on existing virtual disk, I''m gonna investigate if there is some way to do that from XenServer.> -getting help on the citrix forum is very hit and miss. you''re lucky to > get an answer very quickly as opposed to here where you typically get > some kind of answer within hours, if not sooner. >this is very important also, seems to be a great community here> It could be that I''m just missing some important aspects of XenServer > that I have yet to figure out. You should try it and see if it fits for > you. > >I''ve Installed it and I''m gonna try it> Now, back to my problems.... > > James > > >Thanks for your time> _______________________________________________ > 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