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    Hosts in a pool have gone offline after reboot

    Scheduled Pinned Locked Moved Management
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    • DanpD Offline
      Danp Pro Support Team @Aeoran
      last edited by

      @Aeoran Yes, that sounds like a good plan.

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      • A Offline
        Aeoran @Danp
        last edited by

        @Danp Is there some documentation you would recommend on how to safely forget a host? I'm confronted with dire warnings on how this will permanently destroy the SRs used by the VMs that used to run on the dead host. So, I want to make really sure I won't be doing something wrong here.

        Thanks!

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        • nikadeN Offline
          nikade Top contributor
          last edited by

          Shared storage should belong to the pool, only local SR should be affected when you forget the old master.
          Just make sure all the slaves know about the new master before doing anything to the old one.

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          • A Offline
            Aeoran @nikade
            last edited by

            @nikade It looks like I cannot get the dead host to rejoin the pool using xe pool-join:

            You attempted an operation that was not allowed.
            reason: Host is already part of a pool
            

            Will I have problems if I try to force it to join with xe pool-join force? A forum post seems to suggest that this may propagate data corruption errors from the dead host to the pool, which is obviously undesireable. So how would I avoid that?

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            • nikadeN Offline
              nikade Top contributor
              last edited by

              Not really sure, I'd ask @olivierlambert to be sure.

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              • DanpD Offline
                Danp Pro Support Team
                last edited by

                What actions did you initially perform to remove the host from the pool?

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                • A Offline
                  Aeoran @Danp
                  last edited by

                  @Danp I didn't do anything. The master host failed on its own and stopped responding to XO.

                  I've rebooted the host and the hardware all seems fine. The logs suggest that XAPI is not running because the database is missing a column (see above, first comment).

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                  • DanpD Offline
                    Danp Pro Support Team
                    last edited by

                    You probably need to forget the host using xe host-forget uuid=UUID where UUID belongs to the old pool master.

                    See prior discussion on this topic -- https://xcp-ng.org/forum/topic/6164/remove-a-host-from-a-pool/14

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                    • A Offline
                      Aeoran @Danp
                      last edited by

                      @Danp How can I preserve or recover the local SRs of the dead host?

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                      • DanpD Offline
                        Danp Pro Support Team @Aeoran
                        last edited by

                        @Aeoran AFAIK, the XAPI database gets wiped whenever you add or remove the host from a pool. You may be able to restore metadata to the old master once it is no longer belongs to the pool, but I can't guarantee that this will work or not produce other issues.

                        If you don't have backups of the VMs, then you should be able to copy the VHD files to another location by accessing the directory /run/sr-mount/<SR UUID>/ on the old master.

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