Re: [ovirt-users] Fake power management?
- Original Message - > From: "mots" > To: "Barak Azulay" > Cc: users@ovirt.org > Sent: Tuesday, November 18, 2014 1:17:49 AM > Subject: AW: [ovirt-users] Fake power management? > > -Ursprüngliche Nachricht- > > > Von:Barak Azulay mailto:bazu...@redhat.com> > > > Gesendet: Mon 17 November 2014 23:30 > > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > > CC: users@ovirt.org <mailto:users@ovirt.org> > > Betreff: Re: AW: [ovirt-users] Fake power management? > > > > Well you can hack the solution in the form of replacing the fencing master > > script to always return success (Eli can help you with that), > > and define an imaginary fencing device on each host ... meaning that the > > fencing command will always succeeds. > > > > This sounds interesting. It's exactly what I need. > > > But this may be risky ... as you might end up with the same VM running on 2 > > hosts. > > As I see it, this would only happen if someone unplugs the network interface. > I know this is a way to break the cluster. If someone unplugs the interface, > then everything gets started twice anyways thanks to pacemaker being > configured to ignore the lack of quorum and it would look silly in front of > the customer. > > > And one last note ... when you disconnect one of the hosts in the demo you > > mentioned, I think you'll be better to disconnect the host that does not > > run the engine ... > > It just gets restarted on the remaining node and resumes operation. It even > remembers which guests ran on which host. > That part is really safe. The storage is configured to only report data as > written when the write operation has finished on all (currently online) > nodes, disk write caches are turned off in lvm.conf. PostreSQL is resilient > enough to survive a crash like this. > > Or am I missing something that might break? Let me know if we missed something This is an interesting demo ;-) > > > Barak > > mots > > > > > ----- Original Message ----- > > > From: "mots" mailto:m...@nepu.moe> > > > > To: "Barak Azulay" mailto:bazu...@redhat.com> > > > > Cc: users@ovirt.org <mailto:users@ovirt.org> > > > Sent: Monday, November 17, 2014 12:58:20 PM > > > Subject: AW: [ovirt-users] Fake power management? > > > > > > Yes, pacemaker manages the engine. That part is working fine, the engine > > > restarts on the remaining node without problems. > > > It's just that the guests don't come back up until the powered down node > > > has > > > been fenced manually. > > > > > > -Ursprüngliche Nachricht- > > > > Von:Barak Azulay mailto:bazu...@redhat.com> > > > > <mailto:bazu...@redhat.com <mailto:bazu...@redhat.com> > > > > > > Gesendet: Mon 17 November 2014 11:35 > > > > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > > > <mailto:p...@a-bot.ch <mailto:p...@a-bot.ch> > > > > > > CC: users@ovirt.org <mailto:users@ovirt.org> <mailto:users@ovirt.org > > > > <mailto:users@ovirt.org> > > > > > Betreff: Re: [ovirt-users] Fake power management? > > > > > > > > > > > > > > > > - Original Message - > > > > > From: "mots" mailto:m...@nepu.moe> > > > > > <mailto:m...@nepu.moe <mailto:m...@nepu.moe> > > > > > > > To: users@ovirt.org <mailto:users@ovirt.org> <mailto:users@ovirt.org > > > > > <mailto:users@ovirt.org> > > > > > > Sent: Friday, November 14, 2014 4:54:08 PM > > > > > Subject: [ovirt-users] Fake power management? > > > > > > > > > > Fake power management? Hello, > > > > > > > > > > I'm building a small demonstration system for our sales team to take > > > > > to a > > > > > customer so that they can show them our solutions. > > > > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > > > > Engine: Runs as a VM on one of the NUCs, which one it runs on is > > > > > determined > > > > > by pacemaker. > > > > > Storage: Also managed by pacemaker, it's drbd backed and accessed > > > > > with > > > > > iscsi. > > > > > oVirt version: 3.5 > > > > > OS: CentOS 6.6 > > > > > >
Re: [ovirt-users] Fake power management?
-Ursprüngliche Nachricht- > Von:Barak Azulay mailto:bazu...@redhat.com> > > Gesendet: Mon 17 November 2014 23:30 > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > CC: users@ovirt.org <mailto:users@ovirt.org> > Betreff: Re: AW: [ovirt-users] Fake power management? > > Well you can hack the solution in the form of replacing the fencing master > script to always return success (Eli can help you with that), > and define an imaginary fencing device on each host ... meaning that the > fencing command will always succeeds. > This sounds interesting. It's exactly what I need. > But this may be risky ... as you might end up with the same VM running on 2 > hosts. As I see it, this would only happen if someone unplugs the network interface. I know this is a way to break the cluster. If someone unplugs the interface, then everything gets started twice anyways thanks to pacemaker being configured to ignore the lack of quorum and it would look silly in front of the customer. > And one last note ... when you disconnect one of the hosts in the demo you > mentioned, I think you'll be better to disconnect the host that does not run > the engine ... It just gets restarted on the remaining node and resumes operation. It even remembers which guests ran on which host. That part is really safe. The storage is configured to only report data as written when the write operation has finished on all (currently online) nodes, disk write caches are turned off in lvm.conf. PostreSQL is resilient enough to survive a crash like this. Or am I missing something that might break? > Barak mots > > - Original Message - > > From: "mots" mailto:m...@nepu.moe> > > > To: "Barak Azulay" mailto:bazu...@redhat.com> > > > Cc: users@ovirt.org <mailto:users@ovirt.org> > > Sent: Monday, November 17, 2014 12:58:20 PM > > Subject: AW: [ovirt-users] Fake power management? > > > > Yes, pacemaker manages the engine. That part is working fine, the engine > > restarts on the remaining node without problems. > > It's just that the guests don't come back up until the powered down node has > > been fenced manually. > > > > -Ursprüngliche Nachricht- > > > Von:Barak Azulay mailto:bazu...@redhat.com> > > > <mailto:bazu...@redhat.com <mailto:bazu...@redhat.com> > > > > > Gesendet: Mon 17 November 2014 11:35 > > > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > > <mailto:p...@a-bot.ch <mailto:p...@a-bot.ch> > > > > > CC: users@ovirt.org <mailto:users@ovirt.org> <mailto:users@ovirt.org > > > <mailto:users@ovirt.org> > > > > Betreff: Re: [ovirt-users] Fake power management? > > > > > > > > > > > > - Original Message - > > > > From: "mots" mailto:m...@nepu.moe> > > > > <mailto:m...@nepu.moe <mailto:m...@nepu.moe> > > > > > > To: users@ovirt.org <mailto:users@ovirt.org> <mailto:users@ovirt.org > > > > <mailto:users@ovirt.org> > > > > > Sent: Friday, November 14, 2014 4:54:08 PM > > > > Subject: [ovirt-users] Fake power management? > > > > > > > > Fake power management? Hello, > > > > > > > > I'm building a small demonstration system for our sales team to take to > > > > a > > > > customer so that they can show them our solutions. > > > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > > > Engine: Runs as a VM on one of the NUCs, which one it runs on is > > > > determined > > > > by pacemaker. > > > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > > > iscsi. > > > > oVirt version: 3.5 > > > > OS: CentOS 6.6 > > > > > > > > The idea is to have our sales representative (or the potential customer > > > > himself) randomly pull the plug on one of the NUCs to show that the > > > > system > > > > stays operational when part of the hardware fails. > > > > > > I assume you are aware that the engine might fence the node it is running > > > on ... > > > Or do you use pacemaker to run the engine as well ? > > > > > > > My problem is that I don't have any way to implement power management, > > > > so > > > > the > > > > Engine can't fence nodes and won't restart guests that were running on > > > > the > > > &
Re: [ovirt-users] Fake power management?
Well you can hack the solution in the form of replacing the fencing master script to always return success (Eli can help you with that), and define an imaginary fencing device on each host ... meaning that the fencing command will always succeeds. But this may be risky ... as you might end up with the same VM running on 2 hosts. And one last note ... when you disconnect one of the hosts in the demo you mentioned, I think you'll be better to disconnect the host that does not run the engine ... Barak - Original Message - > From: "mots" > To: "Barak Azulay" > Cc: users@ovirt.org > Sent: Monday, November 17, 2014 12:58:20 PM > Subject: AW: [ovirt-users] Fake power management? > > Yes, pacemaker manages the engine. That part is working fine, the engine > restarts on the remaining node without problems. > It's just that the guests don't come back up until the powered down node has > been fenced manually. > > -Ursprüngliche Nachricht- > > Von:Barak Azulay mailto:bazu...@redhat.com> > > > Gesendet: Mon 17 November 2014 11:35 > > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > > CC: users@ovirt.org <mailto:users@ovirt.org> > > Betreff: Re: [ovirt-users] Fake power management? > > > > > > > > - Original Message - > > > From: "mots" mailto:m...@nepu.moe> > > > > To: users@ovirt.org <mailto:users@ovirt.org> > > > Sent: Friday, November 14, 2014 4:54:08 PM > > > Subject: [ovirt-users] Fake power management? > > > > > > Fake power management? Hello, > > > > > > I'm building a small demonstration system for our sales team to take to a > > > customer so that they can show them our solutions. > > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > > Engine: Runs as a VM on one of the NUCs, which one it runs on is > > > determined > > > by pacemaker. > > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > > iscsi. > > > oVirt version: 3.5 > > > OS: CentOS 6.6 > > > > > > The idea is to have our sales representative (or the potential customer > > > himself) randomly pull the plug on one of the NUCs to show that the > > > system > > > stays operational when part of the hardware fails. > > > > I assume you are aware that the engine might fence the node it is running > > on ... > > Or do you use pacemaker to run the engine as well ? > > > > > My problem is that I don't have any way to implement power management, so > > > the > > > Engine can't fence nodes and won't restart guests that were running on > > > the > > > node which lost power. In pacemaker I can just configure fencing over SSH > > > or > > > even disable the requirement to do so completely. Is there something > > > similar > > > for oVirt, so that the Engine will consider a node which it can't connect > > > to > > > to be powered down? > > > > > > Regards, > > > > > > mots > > > > > > ___ > > > Users mailing list > > > Users@ovirt.org <mailto:Users@ovirt.org> > > > http://lists.ovirt.org/mailman/listinfo/users > > > <http://lists.ovirt.org/mailman/listinfo/users> > > > > > > > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
Yes, pacemaker manages the engine. That part is working fine, the engine restarts on the remaining node without problems. It's just that the guests don't come back up until the powered down node has been fenced manually. -Ursprüngliche Nachricht- > Von:Barak Azulay mailto:bazu...@redhat.com> > > Gesendet: Mon 17 November 2014 11:35 > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > CC: users@ovirt.org <mailto:users@ovirt.org> > Betreff: Re: [ovirt-users] Fake power management? > > > > - Original Message - > > From: "mots" mailto:m...@nepu.moe> > > > To: users@ovirt.org <mailto:users@ovirt.org> > > Sent: Friday, November 14, 2014 4:54:08 PM > > Subject: [ovirt-users] Fake power management? > > > > Fake power management? Hello, > > > > I'm building a small demonstration system for our sales team to take to a > > customer so that they can show them our solutions. > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > Engine: Runs as a VM on one of the NUCs, which one it runs on is determined > > by pacemaker. > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > iscsi. > > oVirt version: 3.5 > > OS: CentOS 6.6 > > > > The idea is to have our sales representative (or the potential customer > > himself) randomly pull the plug on one of the NUCs to show that the system > > stays operational when part of the hardware fails. > > I assume you are aware that the engine might fence the node it is running on > ... > Or do you use pacemaker to run the engine as well ? > > > My problem is that I don't have any way to implement power management, so > > the > > Engine can't fence nodes and won't restart guests that were running on the > > node which lost power. In pacemaker I can just configure fencing over SSH or > > even disable the requirement to do so completely. Is there something similar > > for oVirt, so that the Engine will consider a node which it can't connect to > > to be powered down? > > > > Regards, > > > > mots > > > > ___ > > Users mailing list > > Users@ovirt.org <mailto:Users@ovirt.org> > > http://lists.ovirt.org/mailman/listinfo/users > > <http://lists.ovirt.org/mailman/listinfo/users> > > > signature.asc Description: OpenPGP digital signature ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
- Original Message - > From: "mots" > To: users@ovirt.org > Sent: Friday, November 14, 2014 4:54:08 PM > Subject: [ovirt-users] Fake power management? > > Fake power management? Hello, > > I'm building a small demonstration system for our sales team to take to a > customer so that they can show them our solutions. > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > Engine: Runs as a VM on one of the NUCs, which one it runs on is determined > by pacemaker. > Storage: Also managed by pacemaker, it's drbd backed and accessed with iscsi. > oVirt version: 3.5 > OS: CentOS 6.6 > > The idea is to have our sales representative (or the potential customer > himself) randomly pull the plug on one of the NUCs to show that the system > stays operational when part of the hardware fails. I assume you are aware that the engine might fence the node it is running on ... Or do you use pacemaker to run the engine as well ? > My problem is that I don't have any way to implement power management, so the > Engine can't fence nodes and won't restart guests that were running on the > node which lost power. In pacemaker I can just configure fencing over SSH or > even disable the requirement to do so completely. Is there something similar > for oVirt, so that the Engine will consider a node which it can't connect to > to be powered down? > > Regards, > > mots > > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
- Original Message - > From: "mots" > To: "Eli Mesika" > Cc: users@ovirt.org > Sent: Sunday, November 16, 2014 12:53:53 PM > Subject: AW: [ovirt-users] Fake power management? > > Hello Eli, > > If I replace "/usr/bin/vdsm-tool service-restart vdsmd" with "echo b > > /proc/sysrc-trigger", will the Engine consider the node to be fenced and > restart the VMs that were running on it on another node? I don't see a > mechanism to inform the engine that this was a "hard" fencing operation and > that it's save to restart the guests. We have a RFE for PM hooks but this was not done or get to a version plan yet So, the only way to release the VMs is to manually confirm that the node was rebooted ... > > Regards, > > mots > > -Ursprüngliche Nachricht- > > Von:Eli Mesika mailto:emes...@redhat.com> > > > Gesendet: Son 16 November 2014 03:00 > > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > > CC: users@ovirt.org <mailto:users@ovirt.org> > > Betreff: Re: [ovirt-users] Fake power management? > > > > > > > > - Original Message - > > > From: "Sandro Bonazzola" > > <mailto:sbona...@redhat.com> > > > > To: "mots" mailto:m...@nepu.moe> >, users@ovirt.org > > > <mailto:users@ovirt.org> > > > Sent: Friday, November 14, 2014 5:15:25 PM > > > Subject: Re: [ovirt-users] Fake power management? > > > > > > Il 14/11/2014 15:54, mots ha scritto: > > > > Hello, > > > > > > > > I'm building a small demonstration system for our sales team to take to > > > > a > > > > customer so that they can show them our solutions. > > > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > > > Engine: Runs as a VM on one of the NUCs, which one it runs on is > > > > determined > > > > by pacemaker. > > > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > > > iscsi. > > > > oVirt version: 3.5 > > > > OS: CentOS 6.6 > > > > > > Just for curiosity, any reason for using pacemaker instead on oVirt > > > Hosted > > > Engine solution? > > > > > > > > > > > The idea is to have our sales representative (or the potential customer > > > > himself) randomly pull the plug on one of the NUCs to show that the > > > > system > > > > stays operational when part of the hardware fails. > > > > My problem is that I don't have any way to implement power management, > > > > so > > > > the Engine can't fence nodes and won't restart guests that were running > > > > on > > > > the node which lost power. In pacemaker I can just configure fencing > > > > over > > > > SSH or even disable the requirement to do so completely. Is there > > > > something > > > > similar for oVirt, so that the Engine will consider a node which it > > > > can't > > > > connect to to be powered down? > > > > Well, we are thinking of adding such ability (Fake power management) mainly > > for testing purpose... > > Meanwhile, I think I have a work-around that may help you. > > > > When we have a connectivity issue with a node, we first try (after a grace > > period) to restart its VDSM via SSH > > this is always done before the hard-fencing (restart via the PM card) and > > can be done no matter if the host has PM configured or not. > > So basically when a connectivity issue is found, you can custom the SSH > > command that restarts VDSM to do whatever you want, even a script or a > > power-down command > > > > look at the result of > > > > > psql -U engine -c "select * from vdc_options where option_name ilike > > > 'SshSoftFencingCommand'" engine > > > > option_id | option_name | option_value > > | version > > ---+---+--+- > >558 | SshSoftFencingCommand | service vdsmd restart > >| 3.0 > >559 | SshSoftFencingCommand | service vdsmd restart > >| 3.1 > >560 | SshSoftFencingCommand | service vdsmd restart > >| 3.2 > >561 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart > >vdsmd | 3.3 &g
Re: [ovirt-users] Fake power management?
Hello Eli, If I replace "/usr/bin/vdsm-tool service-restart vdsmd" with "echo b > /proc/sysrc-trigger", will the Engine consider the node to be fenced and restart the VMs that were running on it on another node? I don't see a mechanism to inform the engine that this was a "hard" fencing operation and that it's save to restart the guests. Regards, mots -Ursprüngliche Nachricht- > Von:Eli Mesika mailto:emes...@redhat.com> > > Gesendet: Son 16 November 2014 03:00 > An: Patrick Lottenbach mailto:p...@a-bot.ch> > > CC: users@ovirt.org <mailto:users@ovirt.org> > Betreff: Re: [ovirt-users] Fake power management? > > > > - Original Message - > > From: "Sandro Bonazzola" mailto:sbona...@redhat.com> > > > To: "mots" mailto:m...@nepu.moe> >, users@ovirt.org > > <mailto:users@ovirt.org> > > Sent: Friday, November 14, 2014 5:15:25 PM > > Subject: Re: [ovirt-users] Fake power management? > > > > Il 14/11/2014 15:54, mots ha scritto: > > > Hello, > > > > > > I'm building a small demonstration system for our sales team to take to a > > > customer so that they can show them our solutions. > > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > > Engine: Runs as a VM on one of the NUCs, which one it runs on is > > > determined > > > by pacemaker. > > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > > iscsi. > > > oVirt version: 3.5 > > > OS: CentOS 6.6 > > > > Just for curiosity, any reason for using pacemaker instead on oVirt Hosted > > Engine solution? > > > > > > > > The idea is to have our sales representative (or the potential customer > > > himself) randomly pull the plug on one of the NUCs to show that the system > > > stays operational when part of the hardware fails. > > > My problem is that I don't have any way to implement power management, so > > > the Engine can't fence nodes and won't restart guests that were running on > > > the node which lost power. In pacemaker I can just configure fencing over > > > SSH or even disable the requirement to do so completely. Is there > > > something > > > similar for oVirt, so that the Engine will consider a node which it can't > > > connect to to be powered down? > > Well, we are thinking of adding such ability (Fake power management) mainly > for testing purpose... > Meanwhile, I think I have a work-around that may help you. > > When we have a connectivity issue with a node, we first try (after a grace > period) to restart its VDSM via SSH > this is always done before the hard-fencing (restart via the PM card) and can > be done no matter if the host has PM configured or not. > So basically when a connectivity issue is found, you can custom the SSH > command that restarts VDSM to do whatever you want, even a script or a > power-down command > > look at the result of > > > psql -U engine -c "select * from vdc_options where option_name ilike > > 'SshSoftFencingCommand'" engine > > option_id | option_name | option_value > | version > ---+---+--+- >558 | SshSoftFencingCommand | service vdsmd restart > | 3.0 >559 | SshSoftFencingCommand | service vdsmd restart > | 3.1 >560 | SshSoftFencingCommand | service vdsmd restart > | 3.2 >561 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd > | 3.3 >562 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd > | 3.4 >563 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd > | 3.5 > > > Please note: > > 1) change only the value that match your cluster version > 2) restart engine so change can take place > 3) restore to default value again after you are done > > Does this may be useful for you ? > > > > > > > > > Regards, > > > > > > mots > > > > > > > > > ___ > > > Users mailing list > > > Users@ovirt.org <mailto:Users@ovirt.org> > > > http://lists.ovirt.org/mailman/listinfo/users > > > <http://lists.ovirt.org/mailman/listinfo/users> > > > > > > > > > -- > > Sandro Bonazzola > > Better technology. Faster innovation. Powered by community collaboration. > > See how it works at redhat.com > > ___ > > Users mailing list > > Users@ovirt.org <mailto:Users@ovirt.org> > > http://lists.ovirt.org/mailman/listinfo/users > > <http://lists.ovirt.org/mailman/listinfo/users> > > > signature.asc Description: OpenPGP digital signature ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
- Original Message - > From: "Sandro Bonazzola" > To: "mots" , users@ovirt.org > Sent: Friday, November 14, 2014 5:15:25 PM > Subject: Re: [ovirt-users] Fake power management? > > Il 14/11/2014 15:54, mots ha scritto: > > Hello, > > > > I'm building a small demonstration system for our sales team to take to a > > customer so that they can show them our solutions. > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > Engine: Runs as a VM on one of the NUCs, which one it runs on is determined > > by pacemaker. > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > iscsi. > > oVirt version: 3.5 > > OS: CentOS 6.6 > > Just for curiosity, any reason for using pacemaker instead on oVirt Hosted > Engine solution? > > > > > The idea is to have our sales representative (or the potential customer > > himself) randomly pull the plug on one of the NUCs to show that the system > > stays operational when part of the hardware fails. > > My problem is that I don't have any way to implement power management, so > > the Engine can't fence nodes and won't restart guests that were running on > > the node which lost power. In pacemaker I can just configure fencing over > > SSH or even disable the requirement to do so completely. Is there > > something > > similar for oVirt, so that the Engine will consider a node which it can't > > connect to to be powered down? Well, we are thinking of adding such ability (Fake power management) mainly for testing purpose... Meanwhile, I think I have a work-around that may help you. When we have a connectivity issue with a node, we first try (after a grace period) to restart its VDSM via SSH this is always done before the hard-fencing (restart via the PM card) and can be done no matter if the host has PM configured or not. So basically when a connectivity issue is found, you can custom the SSH command that restarts VDSM to do whatever you want, even a script or a power-down command look at the result of > psql -U engine -c "select * from vdc_options where option_name ilike > 'SshSoftFencingCommand'" engine option_id | option_name | option_value | version ---+---+--+- 558 | SshSoftFencingCommand | service vdsmd restart| 3.0 559 | SshSoftFencingCommand | service vdsmd restart| 3.1 560 | SshSoftFencingCommand | service vdsmd restart| 3.2 561 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd | 3.3 562 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd | 3.4 563 | SshSoftFencingCommand | /usr/bin/vdsm-tool service-restart vdsmd | 3.5 Please note: 1) change only the value that match your cluster version 2) restart engine so change can take place 3) restore to default value again after you are done Does this may be useful for you ? > > > > Regards, > > > > mots > > > > > > ___ > > Users mailing list > > Users@ovirt.org > > http://lists.ovirt.org/mailman/listinfo/users > > > > > -- > Sandro Bonazzola > Better technology. Faster innovation. Powered by community collaboration. > See how it works at redhat.com > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
Well, I haven't found a way to make sure the Engines storage comes up before the Engine is attemting to start. -Ursprüngliche Nachricht- > Von:Sandro Bonazzola mailto:sbona...@redhat.com> > > Gesendet: Fre 14 November 2014 16:13 > An: Patrick Lottenbach mailto:p...@a-bot.ch> >; > users@ovirt.org <mailto:users@ovirt.org> > Betreff: Re: [ovirt-users] Fake power management? > > Il 14/11/2014 15:54, mots ha scritto: > > Hello, > > > > I'm building a small demonstration system for our sales team to take to a > > customer so that they can show them our solutions. > > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > > Engine: Runs as a VM on one of the NUCs, which one it runs on is determined > > by pacemaker. > > Storage: Also managed by pacemaker, it's drbd backed and accessed with > > iscsi. > > oVirt version: 3.5 > > OS: CentOS 6.6 > > Just for curiosity, any reason for using pacemaker instead on oVirt Hosted > Engine solution? > > > > > The idea is to have our sales representative (or the potential customer > > himself) randomly pull the plug on one of the NUCs to show that the system > > stays operational when part of the hardware fails. > > My problem is that I don't have any way to implement power management, so > > the Engine can't fence nodes and won't restart guests that were running on > > the node which lost power. In pacemaker I can just configure fencing over > > SSH or even disable the requirement to do so completely. Is there something > > similar for oVirt, so that the Engine will consider a node which it can't > > connect to to be powered down? > > > > Regards, > > > > mots > > > > > > ___ > > Users mailing list > > Users@ovirt.org <mailto:Users@ovirt.org> > > http://lists.ovirt.org/mailman/listinfo/users > > <http://lists.ovirt.org/mailman/listinfo/users> > > > > > -- > Sandro Bonazzola > Better technology. Faster innovation. Powered by community collaboration. > See how it works at redhat.com > signature.asc Description: OpenPGP digital signature ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
Re: [ovirt-users] Fake power management?
Il 14/11/2014 15:54, mots ha scritto: > Hello, > > I'm building a small demonstration system for our sales team to take to a > customer so that they can show them our solutions. > Hardware: Two Intel NUC's, a 4 port switch and a laptop. > Engine: Runs as a VM on one of the NUCs, which one it runs on is determined > by pacemaker. > Storage: Also managed by pacemaker, it's drbd backed and accessed with iscsi. > oVirt version: 3.5 > OS: CentOS 6.6 Just for curiosity, any reason for using pacemaker instead on oVirt Hosted Engine solution? > > The idea is to have our sales representative (or the potential customer > himself) randomly pull the plug on one of the NUCs to show that the system > stays operational when part of the hardware fails. > My problem is that I don't have any way to implement power management, so the > Engine can't fence nodes and won't restart guests that were running on > the node which lost power. In pacemaker I can just configure fencing over SSH > or even disable the requirement to do so completely. Is there something > similar for oVirt, so that the Engine will consider a node which it can't > connect to to be powered down? > > Regards, > > mots > > > ___ > Users mailing list > Users@ovirt.org > http://lists.ovirt.org/mailman/listinfo/users > -- Sandro Bonazzola Better technology. Faster innovation. Powered by community collaboration. See how it works at redhat.com ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
[ovirt-users] Fake power management?
Hello, I'm building a small demonstration system for our sales team to take to a customer so that they can show them our solutions. Hardware: Two Intel NUC's, a 4 port switch and a laptop. Engine: Runs as a VM on one of the NUCs, which one it runs on is determined by pacemaker. Storage: Also managed by pacemaker, it's drbd backed and accessed with iscsi. oVirt version: 3.5 OS: CentOS 6.6 The idea is to have our sales representative (or the potential customer himself) randomly pull the plug on one of the NUCs to show that the system stays operational when part of the hardware fails. My problem is that I don't have any way to implement power management, so the Engine can't fence nodes and won't restart guests that were running on the node which lost power. In pacemaker I can just configure fencing over SSH or even disable the requirement to do so completely. Is there something similar for oVirt, so that the Engine will consider a node which it can't connect to to be powered down? Regards, mots signature.asc Description: OpenPGP digital signature ___ Users mailing list Users@ovirt.org http://lists.ovirt.org/mailman/listinfo/users
