Re: [DRBD-user] Adding a second volume to a resource and making it UpToDate
On Wed, Sep 01, 2021 at 09:05:19AM +0200, Joel Colledge wrote: > > I meant just put Pacemaker in maintenance mode and do the rest > manually. So no "pcs cluster standby". Perhaps "pcs resource disable" > would be a better solution. In any case, you need to make sure DRBD is > not being used on either node before doing the "drbdadm primary > --force" steps. Understood. Thank you, Joel! ___ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user
Re: [DRBD-user] Adding a second volume to a resource and making it UpToDate
> Thank you for your reply, Joel! I'm a little confused. If I understand > you correctly, what I should have done is: > > pcs property set maintenance-mode=true > pcs cluster standby storage1 > > How would the combination of putting Pacemaker in maintenance mode and > then trying to standby a cluster member work? Or maybe what you are > saying is that the standby command would have not really done anything > (because maintenance mode was active), but running the command and > then running the unstandby command would have been enough to trigger a > change in the "Inconsistent" state? I meant just put Pacemaker in maintenance mode and do the rest manually. So no "pcs cluster standby". Perhaps "pcs resource disable" would be a better solution. In any case, you need to make sure DRBD is not being used on either node before doing the "drbdadm primary --force" steps. Regards, Joel ___ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user
Re: [DRBD-user] Adding a second volume to a resource and making it UpToDate
On Tue, Aug 31, 2021 at 01:58:24PM +0200, Joel Colledge wrote: > > So, maybe this is a question for the Pacemaker mailing list, but what > > did I do wrong here? When adding a second volume to a resource, what is > > the proper way to change its state from Inconsistent to UpToDate? > > I would say that you're on the right track, but put Pacemaker into > maintenance mode while making the changes. Thank you for your reply, Joel! I'm a little confused. If I understand you correctly, what I should have done is: pcs property set maintenance-mode=true pcs cluster standby storage1 How would the combination of putting Pacemaker in maintenance mode and then trying to standby a cluster member work? Or maybe what you are saying is that the standby command would have not really done anything (because maintenance mode was active), but running the command and then running the unstandby command would have been enough to trigger a change in the "Inconsistent" state? > Taking a step back - why do you need to add a second volume to a > resource which is in use? Multiple volumes are used to form > consistency groups. For instance, placing database logs and tables on > different backing storage. When you do that you generally know at the > time you set it up, so there is no need to add a second volume to a > resource which is in use. Is there any reason you can't just create a > second DRBD resource for your new volume? In hindsight, I probably should have used a second resource. The core issue that I'm addressing is that we are running Red Hat Enterprise Virtualization on top of DRBD/Pacemaker. We are planning an upgrade to RHEV 4.4 which requires a new storage domain in RHEV. And we had no free space in our iSCSI environment to use for a new storage domain. So, we added new drives to our storage servers. Thanks, Bryan ___ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user
Re: [DRBD-user] Adding a second volume to a resource and making it UpToDate
Hi Bryan, > In the very last post in this thread there is this: > > "DRBD requires some intervention to enable the volume. The > simplest method to get the new volume working would be to demote > the resource to the "Secondary" role and then promote it to the > "Primary" role again, using drbdadm primary --force resourcename. > The newly added volume will then perform a full sync and should > end up "UpToDate" once the sync finishes." Yes, this is the way to do it at the moment. Doing it without any downtime is tricky. > Here I made a very bad mistake. I issued "pcs cluster standby storage1" > to put the primary storage into standby mode. However, with Volume 1 > in an Inconsistent state on both servers, what happened, was that > storage1 went into secondary mode and storage2 (the secondary server) > failed to be elevated to primary. At this point all of our storage went > off line, with both storage servers in secondary mode. > > So, maybe this is a question for the Pacemaker mailing list, but what > did I do wrong here? When adding a second volume to a resource, what is > the proper way to change its state from Inconsistent to UpToDate? I would say that you're on the right track, but put Pacemaker into maintenance mode while making the changes. Taking a step back - why do you need to add a second volume to a resource which is in use? Multiple volumes are used to form consistency groups. For instance, placing database logs and tables on different backing storage. When you do that you generally know at the time you set it up, so there is no need to add a second volume to a resource which is in use. Is there any reason you can't just create a second DRBD resource for your new volume? Best regards, Joel ___ Star us on GITHUB: https://github.com/LINBIT drbd-user mailing list drbd-user@lists.linbit.com https://lists.linbit.com/mailman/listinfo/drbd-user
