Hi, We are planning to have LVM being used over a network of 3 h/w machines(500 GB Disk each) Each hardware machine will have 2-3 domUs. Can we store these domUs as a Logical Volumes stored across Network of these 3 machines? Can one DomU exceed the 500 GB (physical drive size) and store say 1 TB of data across the networked Physical Volumes? Has anyone done this before? Thanks and regards, Rajan Chandi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
In my organisation we''ve setup CLVM using a iSCSI shared storage backend to achieve this purpose. It works well, live migration works and speeds are good. If using locally attached discs, the only way to have the data stored across the network is something like DRDB to perform raid1 network mirroring. However, you''ll lose half your space and create a lot of network traffic in this approach. Cheers, On Mon, Oct 26, 2009 at 10:45 AM, rajan chandi <chandi.rajan@gmail.com>wrote:> > Hi, > > We are planning to have LVM being used over a network of 3 h/w machines(500 > GB Disk each) > Each hardware machine will have 2-3 domUs. > > Can we store these domUs as a Logical Volumes stored across Network of > these 3 machines? > > Can one DomU exceed the 500 GB (physical drive size) and store say 1 TB of > data across the networked Physical Volumes? > > Has anyone done this before? > > Thanks and regards, > Rajan Chandi > > > > _______________________________________________ > 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
Very interesting. I was hoping that LVM2 could work with drives attached with other computers on the network. Cheers Rajan On Mon, Oct 26, 2009 at 5:07 PM, Stephen Ross < stephen.ross1986@googlemail.com> wrote:> In my organisation we''ve setup CLVM using a iSCSI shared storage backend to > achieve this purpose. It works well, live migration works and speeds are > good. > > If using locally attached discs, the only way to have the data stored > across the network is something like DRDB to perform raid1 network > mirroring. However, you''ll lose half your space and create a lot of network > traffic in this approach. > > Cheers, > > On Mon, Oct 26, 2009 at 10:45 AM, rajan chandi <chandi.rajan@gmail.com>wrote: > >> >> Hi, >> >> We are planning to have LVM being used over a network of 3 h/w >> machines(500 GB Disk each) >> Each hardware machine will have 2-3 domUs. >> >> Can we store these domUs as a Logical Volumes stored across Network of >> these 3 machines? >> >> Can one DomU exceed the 500 GB (physical drive size) and store say 1 TB of >> data across the networked Physical Volumes? >> >> Has anyone done this before? >> >> Thanks and regards, >> Rajan Chandi >> >> >> >> _______________________________________________ >> 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
On Mon, Oct 26, 2009 at 8:14 AM, rajan chandi <chandi.rajan@gmail.com> wrote:> Very interesting. I was hoping that LVM2 could work with drives attached > with other computers on the network.it can, if those other computers share their drives. you can run an iSCSI target, NBD server, or vblade on each machine; then join''em all with cLVM. not for the faint of heart, though, and redundancy isn''t easy either. DRBD is a slightly different configuration where you definitely get some failure protection; but it''s typically limited to just 2 nodes. if you need more than that, you end layering both solutions. again, totally doable; but you have to design the solution yourself. -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks Javier for setup ideas. We are using ServerLoft Dedicated hosting. So, don''t have much control over what can be done from a hardware perspective. Their servers are good and cheap. Only problem is that they don''t support anything above 500 GBx2 with RAID 1. We are trying to figure a work-around to use the storage across the servers more efficiently. Is there a possibility to use LVM2 with some kind of NFS/GFS? Regards Rajan On Mon, Oct 26, 2009 at 10:21 AM, Javier Guerra <javier@guerrag.com> wrote:> On Mon, Oct 26, 2009 at 8:14 AM, rajan chandi <chandi.rajan@gmail.com> > wrote: > > Very interesting. I was hoping that LVM2 could work with drives attached > > with other computers on the network. > > it can, if those other computers share their drives. > > you can run an iSCSI target, NBD server, or vblade on each machine; > then join''em all with cLVM. not for the faint of heart, though, and > redundancy isn''t easy either. > > DRBD is a slightly different configuration where you definitely get > some failure protection; but it''s typically limited to just 2 nodes. > if you need more than that, you end layering both solutions. again, > totally doable; but you have to design the solution yourself. > > -- > Javier >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Mon, Oct 26, 2009 at 10:50 PM, rajan chandi <chandi.rajan@gmail.com> wrote:> Thanks Javier for setup ideas. > > We are using ServerLoft Dedicated hosting. > So, don''t have much control over what can be done from a hardware > perspective. > Their servers are good and cheap. > > Only problem is that they don''t support anything above 500 GBx2 with RAID 1. > > We are trying to figure a work-around to use the storage across the servers > more efficiently. > > Is there a possibility to use LVM2 with some kind of NFS/GFS?If by "efficiently" you mean "I need one server to have more storage than what is physically available to it", then yes, it might be possible. I''d generally say it''s not worthed though. Way too much effort. For example : - you have two servers with 500G disk each - both is setup using partitions, one 50G (system) and one 450G (for LVM PV). These are approximate values. - you share second partition of server 2 using iscsi - import iscsi share from server 2 on server 1 - setup LVM on server 1 using its own 2nd partition and server 2''s iscsi share. You''ll get 900G VG. Gotcha in this setup: if server 2 is dead, you might lose your data. Workaround: you need 1 other server : say server 3. The setup now becomes: - server 2 and server 3 share its partition using iscsi - server 1 import iscsi share from 2 and 3, and setup it as mirror using Linux md - setup LVM on server 1 using its own 2nd partition and a mirror of server 2 and 3''s iscsi share In this setup server 2 and 3 mirrors each other''s data, so you can have a single disk or stripe (RAID0). Gotcha in this setup: you need to fine-tune iscsi so that in doesn''t retry forever when server 2 or 3 is dead. See why I say it''s too much effort? It''d be MUCH easier to simply buy a 2U server with 14 3.5" drives, have them host it (so it''s colo instead of dedicated server), and use it as iscsi/nfs server. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks Fazar. I was looking for least expensive possible options. ServerLoft being one of them but limitation of 500 GB per machine max. It sounds like I should figure out other better options which will provide expandability at lower costs. Regards Rajan On Tue, Oct 27, 2009 at 8:42 AM, Fajar A. Nugraha <fajar@fajar.net> wrote:> On Mon, Oct 26, 2009 at 10:50 PM, rajan chandi <chandi.rajan@gmail.com> > wrote: > > Thanks Javier for setup ideas. > > > > We are using ServerLoft Dedicated hosting. > > So, don''t have much control over what can be done from a hardware > > perspective. > > Their servers are good and cheap. > > > > Only problem is that they don''t support anything above 500 GBx2 with RAID > 1. > > > > We are trying to figure a work-around to use the storage across the > servers > > more efficiently. > > > > Is there a possibility to use LVM2 with some kind of NFS/GFS? > > If by "efficiently" you mean "I need one server to have more storage > than what is physically available to it", then yes, it might be > possible. I''d generally say it''s not worthed though. Way too much > effort. > > For example : > - you have two servers with 500G disk each > - both is setup using partitions, one 50G (system) and one 450G (for > LVM PV). These are approximate values. > - you share second partition of server 2 using iscsi > - import iscsi share from server 2 on server 1 > - setup LVM on server 1 using its own 2nd partition and server 2''s > iscsi share. You''ll get 900G VG. > > Gotcha in this setup: if server 2 is dead, you might lose your data. > Workaround: you need 1 other server : say server 3. The setup now becomes: > > - server 2 and server 3 share its partition using iscsi > - server 1 import iscsi share from 2 and 3, and setup it as mirror > using Linux md > - setup LVM on server 1 using its own 2nd partition and a mirror of > server 2 and 3''s iscsi share > > In this setup server 2 and 3 mirrors each other''s data, so you can > have a single disk or stripe (RAID0). > Gotcha in this setup: you need to fine-tune iscsi so that in doesn''t > retry forever when server 2 or 3 is dead. > > See why I say it''s too much effort? > It''d be MUCH easier to simply buy a 2U server with 14 3.5" drives, > have them host it (so it''s colo instead of dedicated server), and use > it as iscsi/nfs server. > > -- > Fajar >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users