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    XO cant Snapshot itself ?

    Scheduled Pinned Locked Moved Solved Xen Orchestra
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    • M Offline
      Meth0d @olivierlambert
      last edited by

      @olivierlambert maybe i missunderstood things, the RAW Disk from my XO VM is the 7TB data disk "[NOBAK] xoa_backup_hdd".
      The system disk is "xoa_sda" is not RAW.

      So i thought excluding the disk with "[NOBAK]" would make me able to snapshot the VM (system disk). So whenever you have attached a RAW device makes you unable to snapshot the VM.

      Detaching it, taking a snapshot and reattaching it would work however?

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      • olivierlambertO Offline
        olivierlambert Vates πŸͺ Co-Founder CEO
        last edited by

        • On XCP-ng 8.2: [NOBAK] will be only used by Xen Orchestra to NOT export the snapshot generated by VM.snapshot method.
        • On XCP-ng 8.3: [NOBAK] will be used by XO to exclude the disk from the VM.snaphot call during an XO backup (since we added that feature in XAPI ourselves)

        In any case, a manual snapshot will snap all the drives.

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        • M Offline
          Momi_V
          last edited by

          You can do this on the cli (in 8.3) via

          xe vm-snapshot new-name-label=newname uuid=vmUUID ignore-vdi-uuids=uuid1,uuid2,uuid3
          

          It is currently not possible in Xen-Orchestra, see
          https://xcp-ng.org/forum/topic/3607/snapshot-backup-exclude-additional-mounted-disk/8?_=1680267126156

          M 1 Reply Last reply Reply Quote 1
          • M Offline
            Meth0d @Momi_V
            last edited by

            Thanks for the heads up. A [NOSNAP] Feature sounds like a good idea though πŸ™‚

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            • olivierlambertO Offline
              olivierlambert Vates πŸͺ Co-Founder CEO
              last edited by

              We have to discuss this internally with @julien-f πŸ™‚

              julien-fJ 1 Reply Last reply Reply Quote 0
              • planedropP Offline
                planedrop Top contributor
                last edited by

                FYI just for future things, a generally better way to make greater than 2TiB disks is to simply span them within the guest OS, so basically for 7TiB just make like 4 2TiB VHD's and then have the VM OS span those disks so they appear as a single disk within the VM.

                I do this all the time, works super well and gives you the ability to still snapshot them, etc....

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                • M Offline
                  Meth0d @planedrop
                  last edited by

                  @planedrop are you using LVM for that or how are u doing that? I never bothered with the problem because i dont have enough local space for 8TB disk snapshots anyways.

                  planedropP 1 Reply Last reply Reply Quote 0
                  • planedropP Offline
                    planedrop Top contributor @Meth0d
                    last edited by

                    @Meth0d Format wise I am using EXT so it's thin provisioned, and since it's all thin provisioned, snapshots only take up the space of the changes to the disk, so you don't really need enough space for 8TB snapshots.

                    As for LVM, you mean in the VMs to manage spanning? So far I've only really had a need to go beyond 2TiB for Windows VMs so I'm just using NTFS with Windows Disk Manager for those spans. But I imagine you could do it with LVM in Linux, not sure if there are better options for it.

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                    • julien-fJ Offline
                      julien-f Vates πŸͺ Co-Founder XO Team @olivierlambert
                      last edited by

                      @olivierlambert Does [NOSNAP] implies [NOBAK]?

                      If not, should we ignore [NOSNAP] when a snapshot is required to backup the VM?

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                      • olivierlambertO Offline
                        olivierlambert Vates πŸͺ Co-Founder CEO
                        last edited by

                        That's a good question and an important choice to make πŸ€”

                        IMHO, the principle of least surprise would tell to ignore [NOSNAP] during a backup. Because I'm afraid people would backup a VM with [NOSNAP] and expect it to be saved. That would be a bad surprise if not. What do you think?

                        julien-fJ 1 Reply Last reply Reply Quote 0
                        • julien-fJ Offline
                          julien-f Vates πŸͺ Co-Founder XO Team @olivierlambert
                          last edited by

                          @olivierlambert I think that [NOSNAP] means that this VDI should not be snapshotted and that ignoring it during backup would be surprising.

                          But your point is valid too, I have no ideal solution, hence my question ^^

                          julien-fJ 1 Reply Last reply Reply Quote 0
                          • julien-fJ Offline
                            julien-f Vates πŸͺ Co-Founder XO Team @julien-f
                            last edited by

                            I don't see a case where one would want [NOSNAP] but not [NOBAK]. Maybe we could require either none or both of them during a backup and not support one without the other?

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                            • olivierlambertO Offline
                              olivierlambert Vates πŸͺ Co-Founder CEO
                              last edited by olivierlambert

                              The situation I can have in mind:

                              • you want your VM to be backup
                              • when you do a manual snapshot, you don't want to snap a disk

                              But why doing this? I don't know, it's hard to predict the need for this… At least, if we choose to NOT doing a backup of this disk with NOSNAP, we MUST tell that clearly in the doc.

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                              • W Offline
                                wilsonqanda
                                last edited by wilsonqanda

                                @julien-f @olivierlambert
                                Was there a resolution on the [NOSNAP] feature just much convenient than going to the CMD each time πŸ™‚ ?

                                In the meantime will be using snippet below so low priority for me:

                                xe vm-snapshot new-name-label=newname uuid=vmUUID ignore-vdi-uuids=uuid1,uuid2,uuid3
                                
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                                • olivierlambertO Offline
                                  olivierlambert Vates πŸͺ Co-Founder CEO
                                  last edited by

                                  You mean [NOBAK]?

                                  W 1 Reply Last reply Reply Quote 0
                                  • W Offline
                                    wilsonqanda @olivierlambert
                                    last edited by wilsonqanda

                                    @olivierlambert Thanks for the quick reply. [NOBAK] works for backup by ignoring VDI with [NOBAK] in its name, but when running manual snapshot like stated above the [NOBAK] still show up in the SR meaning it made a copy of the [NOBACK].

                                    Ideally with [NOBAK] it should not take snapshot or backup right or am i understanding it incorrectly? Does this only apply to automated BACKUP & SNAPSHOT only?
                                    94bcd9f6-3051-46f1-91c8-729e4f289d43-image.png

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                                    • GheppyG Offline
                                      Gheppy
                                      last edited by Gheppy

                                      From my point of view, it should be with "OR" and if the condition is fulfilled to execute.
                                      E.g :

                                      • if I have "[NOSNAP] 'VM name' " not to execute snapshoot
                                      • if I have "[NOBAK] 'Vm name' " not to execute backup
                                      • if I have "[NOSNAP] [NOBAK] 'Vm name' " not to execute snapshot and backup
                                        But if you make a backup, remove only what is with [NOBAK]
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                                      • olivierlambertO Offline
                                        olivierlambert Vates πŸͺ Co-Founder CEO
                                        last edited by

                                        Opinion @julien-f ?

                                        julien-fJ 1 Reply Last reply Reply Quote 0
                                        • GheppyG Offline
                                          Gheppy
                                          last edited by

                                          This is what I was thinking

                                          • [NOSNAP] to be like SDA and disk 3
                                          • [NOBAK] to be with SDA and disk 2
                                          • In both cases disk 4 is excluded

                                          66a42055-8a10-4b46-a203-0dd3da2e9b54-image.png

                                          W 1 Reply Last reply Reply Quote 1
                                          • W Offline
                                            wilsonqanda @Gheppy
                                            last edited by wilsonqanda

                                            @Gheppy Wow great illustration πŸ™‚ i think this is perfect but only if it is feasible to implement it now...

                                            FYI as a side note I notice that when I do ignore-vdi-uuids=uuid1,uuid2,uuid3 I notice that when I reload snapshots of the VM the ignore vdi(s) disappear in the Disks section. Which makes logical sense as those ignore-vdi-uuids are not part off the list that are snapshotted. But it's a bit of an inconvenient to add VDI back in as those vdi should still be part of the disk just not part of the snapshots. But otherwise it works great.

                                            To snapshot do the following to ignore certain vdi(s):

                                            xe vm-snapshot new-name-label="newname_YYYY-MM-DDTHH:MM:SS.sssZ" uuid=vmUUID ignore-vdi-uuids=uuid1
                                            

                                            where uuid1=[NOSNAP] TESTING
                                            e9a2aa43-a1ce-4616-99df-bdaada587151-image.png

                                            Once reload the [NOSNAP] disappear:
                                            74a25d27-1b2e-4968-844c-799ab2dc1742-image.png

                                            Beside that this is the best workaround for now and this little inconvenience is not a big deal. But in case someone need to understand it hopefully I added enough detail to clarify this content for future readers.

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