Tomoki Taniguchi
2007-Nov-06 07:26 UTC
[Xen-users] does live migration require a cluster aware filesystem?
I can''t seem to get find a straight answer to this question, so i decided to ask it directly. If i want to do a live migration between two xen servers which has the domainU filesystem shared to them using nbd, does the filesystem have to be cluster aware like gfs? or can it be ext3 since technically the two servers should never be writing to the filesystem at the same time? I was thinking since windows servers with ntfs filesystems doesn''t seem to have a problem, maybe the default ext3 would work just fine? TIA, Tomoki _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2007-Nov-06 07:41 UTC
Re: [Xen-users] does live migration require a cluster aware filesystem?
Tomoki Taniguchi wrote:> I can''t seem to get find a straight answer to this question, > so i decided to ask it directly. > > If i want to do a live migration between two xen servers which has the domainU > filesystem shared to them using nbd, does the filesystem have to be > cluster aware like > gfs? or can it be ext3 since technically the two servers should never > be writing to > the filesystem at the same time? >If you store domU disks as files on dom0, then yes, you need a cluster file system. If you store domU disks as LVM (or other block device) on dom0, then no. Both dom0 involved in migration simply need to have access to the same block device. For example, you can have a server exporting LVs via iscsi, and several dom0''s using them as domU storage.> I was thinking since windows servers with ntfs filesystems doesn''t > seem to have a problem, >Really? Are you saying that two windows servers can mount the same ntfs-formatted block device at the SAME TIME without a problem? Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Tomoki Taniguchi
2007-Nov-06 12:00 UTC
Re: [Xen-users] does live migration require a cluster aware filesystem?
On Nov 6, 2007 4:41 PM, Fajar A. Nugraha <fajar@telkom.net.id> wrote:> Tomoki Taniguchi wrote: > > I can''t seem to get find a straight answer to this question, > > so i decided to ask it directly. > > > > If i want to do a live migration between two xen servers which has the domainU > > filesystem shared to them using nbd, does the filesystem have to be > > cluster aware like > > gfs? or can it be ext3 since technically the two servers should never > > be writing to > > the filesystem at the same time? > > > If you store domU disks as files on dom0, then yes, you need a cluster > file system. > If you store domU disks as LVM (or other block device) on dom0, then no. > Both dom0 involved in migration simply need to have access to the same > block device. For example, you can have a server exporting LVs via > iscsi, and several dom0''s using them as domU storage.thank you. can i assume this applies to nbd shared devices as well?> > > I was thinking since windows servers with ntfs filesystems doesn''t > > seem to have a problem, > > > > Really? Are you saying that two windows servers can mount the same > ntfs-formatted block device at the SAME TIME without a problem?no what i mean is that it is possible to do a live migration of windows domUs. and as far as i know NTFS is not cluster-aware. so it stands to reason that ext3 should be able to with stand a live migration as well.> > Regards, > > Fajar > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >-- Tomoki Taniguchi _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2007-Nov-07 05:44 UTC
Re: [Xen-users] does live migration require a cluster aware filesystem?
Tomoki Taniguchi wrote:> On Nov 6, 2007 4:41 PM, Fajar A. Nugraha <fajar@telkom.net.id> wrote: > >> Tomoki Taniguchi wrote: >> >>> I can''t seem to get find a straight answer to this question, >>> so i decided to ask it directly. >>> >>> If i want to do a live migration between two xen servers which has the domainU >>> filesystem shared to them using nbd, does the filesystem have to be >>> cluster aware like >>> gfs? or can it be ext3 since technically the two servers should never >>> be writing to >>> the filesystem at the same time? >>> >>> >> If you store domU disks as files on dom0, then yes, you need a cluster >> file system. >> If you store domU disks as LVM (or other block device) on dom0, then no. >> Both dom0 involved in migration simply need to have access to the same >> block device. For example, you can have a server exporting LVs via >> iscsi, and several dom0''s using them as domU storage. >> > > thank you. can i assume this applies to nbd shared devices as well? > >Yes.>>> I was thinking since windows servers with ntfs filesystems doesn''t >>> seem to have a problem, >>> >>> >> Really? Are you saying that two windows servers can mount the same >> ntfs-formatted block device at the SAME TIME without a problem? >> > > no what i mean is that it is possible to do a live migration of windows > domUs. and as far as i know NTFS is not cluster-aware. so it stands > to reason that ext3 should be able to with stand a live migration as well. > >Perhaps I misunderstood your question. If you store your domU storage as files on dom0, then dom0 filesystem needs to be cluster aware for live migration to work. However, no such requirement apply for domU. So if your domU is just a normal, non-cluster server, then ext3 will work just fine on domU. Regards, Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Chris Fanning
2007-Nov-07 09:53 UTC
Re: [Xen-users] does live migration require a cluster aware filesystem?
Hi, I am under the impression that live migration requires the domU''s de be on block devices to work properly. You might want to look at AoE. Saludos. Chris. On 11/7/07, Fajar A. Nugraha <fajar@telkom.net.id> wrote:> Tomoki Taniguchi wrote: > > On Nov 6, 2007 4:41 PM, Fajar A. Nugraha <fajar@telkom.net.id> wrote: > > > >> Tomoki Taniguchi wrote: > >> > >>> I can''t seem to get find a straight answer to this question, > >>> so i decided to ask it directly. > >>> > >>> If i want to do a live migration between two xen servers which has the domainU > >>> filesystem shared to them using nbd, does the filesystem have to be > >>> cluster aware like > >>> gfs? or can it be ext3 since technically the two servers should never > >>> be writing to > >>> the filesystem at the same time? > >>> > >>> > >> If you store domU disks as files on dom0, then yes, you need a cluster > >> file system. > >> If you store domU disks as LVM (or other block device) on dom0, then no. > >> Both dom0 involved in migration simply need to have access to the same > >> block device. For example, you can have a server exporting LVs via > >> iscsi, and several dom0''s using them as domU storage. > >> > > > > thank you. can i assume this applies to nbd shared devices as well? > > > > > Yes. > >>> I was thinking since windows servers with ntfs filesystems doesn''t > >>> seem to have a problem, > >>> > >>> > >> Really? Are you saying that two windows servers can mount the same > >> ntfs-formatted block device at the SAME TIME without a problem? > >> > > > > no what i mean is that it is possible to do a live migration of windows > > domUs. and as far as i know NTFS is not cluster-aware. so it stands > > to reason that ext3 should be able to with stand a live migration as well. > > > > > > Perhaps I misunderstood your question. > If you store your domU storage as files on dom0, then dom0 filesystem > needs to be cluster aware for live migration to work. > > However, no such requirement apply for domU. So if your domU is just a > normal, non-cluster server, then ext3 will work just fine on domU. > > Regards, > > Fajar > > _______________________________________________ > 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
Javier Guerra Giraldez
2007-Nov-07 12:43 UTC
Re: [Xen-users] does live migration require a cluster aware filesystem?
On Wednesday 07 November 2007, Chris Fanning wrote:> I am under the impression that live migration requires the domU''s de > be on block devices to work properly.not necessarily, it could be files on an NFS server (not very efficient, of course) the underlying requirement is that since the configuration travels from one box to the other unchanged, the storage for DomU''s have to be accessible from both Dom0''s with _the same name_ that''s means either shared block devices or a shared filesystem -- Javier _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hello, I''m in need to installing the domain 0 ''xm'' tool on top of a XenSource Enterprise 4.0 installation. 1) Has anyone done this? 2) Is it feasible to have both ''xm'' and ''xe'' in the same domain? 3) Where can I get the public version of ''xm'' to install by itself? Or do I need to install a full Xen kit and extract the files manually? Thank you in advance. Roger Cruz _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users