Hi. I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. I''m trying to do live migration, and seems to work (despite it''s taking 1m30 to execute xm migrate, on a 100mbit link). These are going to be managed by heartbeat, and there''s something I cannot understand: I''ve created the VM using virt-manager, and it placed the config in /var/lib/xend/domains on the first dom0. This config is NOT replicated accross xen servers. I''d like to know: is it possible to make Xen servers communicate and share VM configs? Or should I place that dir on a shared location (drbd) between the two? Thanks -- Lorenzo Milesi - lorenzo.milesi@yetopen.it YetOpen S.r.l. - http://www.yetopen.it/ Via Carlo Torri Tarelli 19 - 23900 Lecco - ITALY - Tel 0341 220 205 - Fax 178 6070 222 GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it -------- D.Lgs. 196/2003 -------- Si avverte che tutte le informazioni contenute in questo messaggio sono riservate ed a uso esclusivo del destinatario. Nel caso in cui questo messaggio Le fosse pervenuto per errore, La invitiamo ad eliminarlo senza copiarlo, a non inoltrarlo a terzi e ad avvertirci non appena possibile. Grazie. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 06/16/11 17:03, Lorenzo Milesi wrote:> Hi. > I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. > I''m trying to do live migration, and seems to work (despite it''s taking 1m30 to execute xm migrate, on a 100mbit link). > These are going to be managed by heartbeat, and there''s something I cannot understand: I''ve created the VM using virt-manager, and it placed the config in /var/lib/xend/domains on the first dom0. This config is NOT replicated accross xen servers. > > I''d like to know: is it possible to make Xen servers communicate and share VM configs? > Or should I place that dir on a shared location (drbd) between the two? > > Thanksif you don''t have shared storage now, there is no way you are doing live migration. My guess is you are doing a plain migration and that is why it takes this long. DRBD is a cheap way to share storage and combine with Xen. B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
I know some people have used opensharedroot for this, but for two nodes it will certainly be overkill :) 2011/6/16 Lorenzo Milesi <lorenzo.milesi@yetopen.it>:> I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. <-------- > I''m trying to do live migration, and seems to work (despite it''s taking 1m30 to execute xm migrate, on a 100mbit link). > These are going to be managed by heartbeat, and there''s something I cannot understand: I''ve created the VM using virt-manager, and it placed the config in /var/lib/xend/domains on the first dom0. This config is NOT replicated accross xen servers. > > I''d like to know: is it possible to make Xen servers communicate and share VM configs?A mechanism for that was never added :/> Or should I place that dir on a shared location (drbd) between the two?as You already run DR:BD for the shared storage, this should be the way to go. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Small addendum.... :) - Oracle nicely solved this by having something like /virtual_machines (ocfs2) /virtual_machines/templates /virtual_machines/deployed/ /virtual_machines/deployed/vm001 /virtual_machines/deployed/vm001/OSdisk.img /virtual_machines/deployed/vm001/Any_Data_disk.img /virtual_machines/deployed/vm001/vm.cfg Of course that means you''d not be using LVM. I''d recommend you move away from virt-manager unless you''re really really focussed on running very few VMs with no VLANs ... Otherwise you''ll end up (manually!) maintaining it''s xml configs. The only thing I ever liked about it is that it reconnects when the VM reboots. For speeding up the live migration, have a look for the patches called "vm-migrate-after". They''re supposed to make things a lot faster just never made it into Xen. Flo _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> if you don''t have shared storage now, there is no way you are doing > live > migration. My guess is you are doing a plain migration and that is why > it takes this long. > DRBD is a cheap way to share storage and combine with Xen.I have DRBD8 in active/active config. VM runs on drbd resources. I also have a drbd+ocfs2 shared directory on both servers. So I do have shared storage. I guess, as Florian said, to place config files in this shared directory. About migration, how do I undestand if I''m doing live or plain migration? thanks -- Lorenzo Milesi - lorenzo.milesi@yetopen.it YetOpen S.r.l. - http://www.yetopen.it/ Via Carlo Torri Tarelli 19 - 23900 Lecco - ITALY - Tel 0341 220 205 - Fax 178 6070 222 GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it -------- D.Lgs. 196/2003 -------- Si avverte che tutte le informazioni contenute in questo messaggio sono riservate ed a uso esclusivo del destinatario. Nel caso in cui questo messaggio Le fosse pervenuto per errore, La invitiamo ad eliminarlo senza copiarlo, a non inoltrarlo a terzi e ad avvertirci non appena possibile. Grazie. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 06/16/11 18:30, Lorenzo Milesi wrote:>> if you don''t have shared storage now, there is no way you are doing >> live >> migration. My guess is you are doing a plain migration and that is why >> it takes this long. >> DRBD is a cheap way to share storage and combine with Xen. > > I have DRBD8 in active/active config. VM runs on drbd resources. > I also have a drbd+ocfs2 shared directory on both servers. > > So I do have shared storage. > I guess, as Florian said, to place config files in this shared directory. > > > About migration, how do I undestand if I''m doing live or plain migration? > thanksOK, nothing said then. Personally I keep the config files seperately on the different servers and sync them by means of csync. But you could have something like OCFS share them across your nodes. Live migration or not: well if your vm keeps on being available doing migration, you''re doing live migration :-) B. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 06/16/2011 11:03 AM, Lorenzo Milesi wrote:> Hi. > I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. > I''m trying to do live migration, and seems to work (despite it''s taking 1m30 to execute xm migrate, on a 100mbit link). > These are going to be managed by heartbeat, and there''s something I cannot understand: I''ve created the VM using virt-manager, and it placed the config in /var/lib/xend/domains on the first dom0. This config is NOT replicated accross xen servers. > > I''d like to know: is it possible to make Xen servers communicate and share VM configs? > Or should I place that dir on a shared location (drbd) between the two? > > ThanksI do this with a small GFS2 partition. Also, 1m30s for a 100Mbit link isn''t unreasonable for a live migration, if your VM(s) have a decent amount of RAM. That RAM needs to be copied to the target, while tracking changes to the memory as the VM is still active during the process. -- Digimer E-Mail: digimer@alteeve.com Freenode handle: digimer Papers and Projects: http://alteeve.com Node Assassin: http://nodeassassin.org "I feel confined, only free to expand myself within boundaries." _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On 16 Jun 2011, at 17:48, Digimer wrote:> Also, 1m30s for a 100Mbit link isn''t unreasonable for a live migration, if your VM(s) have a decent amount of RAM. That RAM needs to be copied to the target, while tracking changes to the memory as the VM is still active during the process.Agreed. 100Mbit/s is really very slow and 1m 30s to copy a VM is respectable. 100Mbit/s can only reach 12.5MB/s theoretically. Even operating at maximum theoretical speeds it would take 82 seconds to copy 1024MB of RAM over a link that slow. Iain _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi Lorenzo, csync2 is great for this. oss.linbit.com/csync2/ cheers Juergen Am 16.06.11 17:03, schrieb Lorenzo Milesi:> Hi. > I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. > I''m trying to do live migration, and seems to work (despite it''s taking 1m30 to execute xm migrate, on a 100mbit link). > These are going to be managed by heartbeat, and there''s something I cannot understand: I''ve created the VM using virt-manager, and it placed the config in /var/lib/xend/domains on the first dom0. This config is NOT replicated accross xen servers. > > I''d like to know: is it possible to make Xen servers communicate and share VM configs? > Or should I place that dir on a shared location (drbd) between the two? > > Thanks_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> Agreed. 100Mbit/s is really very slow and 1m 30s to copy a VM is > respectable.ok thanks. I''ll see on production if I have a gigabit switch, or I should migrate using the crossover cable (1Gbit). thanks -- Lorenzo Milesi - lorenzo.milesi@yetopen.it YetOpen S.r.l. - http://www.yetopen.it/ Via Carlo Torri Tarelli 19 - 23900 Lecco - ITALY - Tel 0341 220 205 - Fax 178 6070 222 GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it -------- D.Lgs. 196/2003 -------- Si avverte che tutte le informazioni contenute in questo messaggio sono riservate ed a uso esclusivo del destinatario. Nel caso in cui questo messaggio Le fosse pervenuto per errore, La invitiamo ad eliminarlo senza copiarlo, a non inoltrarlo a terzi e ad avvertirci non appena possibile. Grazie. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> csync2 is great for this. > > oss.linbit.com/csync2/indeed, easy and fast. I used csync in the past for other purposes... thanks again _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
A cross over cable will limit you to two physical nodes in your pool. If you use a gigabit switch, then you can easily add more physical nodes as needed. -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Lorenzo Milesi Sent: Friday, June 17, 2011 2:26 AM To: Iain Kay Cc: xen-users@lists.xensource.com; Digimer Subject: Re: [Xen-users] Share config between servers> Agreed. 100Mbit/s is really very slow and 1m 30s to copy a VM is > respectable.ok thanks. I''ll see on production if I have a gigabit switch, or I should migrate using the crossover cable (1Gbit). thanks -- Lorenzo Milesi - lorenzo.milesi@yetopen.it YetOpen S.r.l. - http://www.yetopen.it/ Via Carlo Torri Tarelli 19 - 23900 Lecco - ITALY - Tel 0341 220 205 - Fax 178 6070 222 GPG/PGP Key-Id: 0xE704E230 - http://keyserver.linux.it -------- D.Lgs. 196/2003 -------- Si avverte che tutte le informazioni contenute in questo messaggio sono riservate ed a uso esclusivo del destinatario. Nel caso in cui questo messaggio Le fosse pervenuto per errore, La invitiamo ad eliminarlo senza copiarlo, a non inoltrarlo a terzi e ad avvertirci non appena possibile. Grazie. _______________________________________________ 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 use puppet for this since with a fair number of dom0 servers that it is easier to manage them using a global set of policies and common files. The same puppet is used for domU too, which is handy. On Fri, Jun 17, 2011 at 3:11 AM, Juergen Gotteswinter <jg@internetx.de> wrote:> Hi Lorenzo, > > csync2 is great for this. > > > oss.linbit.com/csync2/ > > cheers > > Juergen > > Am 16.06.11 17:03, schrieb Lorenzo Milesi: >> >> Hi. >> I''ve installed two physical servers with Debian 6, Xen 4 and drbd8. >> I''m trying to do live migration, and seems to work (despite it''s taking >> 1m30 to execute xm migrate, on a 100mbit link). >> These are going to be managed by heartbeat, and there''s something I cannot >> understand: I''ve created the VM using virt-manager, and it placed the config >> in /var/lib/xend/domains on the first dom0. This config is NOT replicated >> accross xen servers. >> >> I''d like to know: is it possible to make Xen servers communicate and share >> VM configs? >> Or should I place that dir on a shared location (drbd) between the two? >> >> 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