Clone VM and exclude a disk

[Egeus]

Hello,
one of my VMs has got normal virtual hard disk (for the operating system) and a huge storage backend, which is directly attached via the VMs-config file (scsi1: /dev/disk/by-id/....., backup=0, size_=....K).

If I do a system update I normally clone the VM, change the MAC and hostname, and test the update procedure on the clone. If everything works fine I will do the update on the original VM.

The problem for me is now that I can't clone the VM (Error: unable to parse volume ID '/dev/disk/by-id...'(500)). Furthermore I dont want to clone the whole data-storage - only the virtual Hard-Disk with the operating-system (scsi0).

I know, that is not exactly that what a clone should do, but is there any possibility to clone a VM and exclue a drive? Or is there any other way I should go?

Thank you very much!

 

[Alwin]

Depending on your Storage (ZFS, thinLVM), you can create a snapshot of the os disk by hand and update the VM directly (rollback if problems). Or use a backup/restore and select 'no backup' in the GUI on the big storage disk.

 

[Egeus]

Thank you for you're answer.
The last time I did the big system updates I did it exactly that way but there are two big problems:
1. If there are problems in the update (which took a little bit longer to find out how to be fixed) the productive machine is down the whole time. Furthermore I had to change system settings that no external user could change data in that time.
2. If the update break something I had to use the backup - but what happend if the backup is not working or the disk for the backups is failing in exactly that moment (and you know - it will fail in exactly that situation)? There is now way how to check if the backup is working 100%!

So in my opinion is always the best way on those virtual enviroments to clone the machine, edit IP and hostname, check if everything is working 100% and only in that case touch the original VM. And not test on the original VM and if something is not working destroy it with a hopefully and never checked backup...

 

[Senin]

Hi!

Did you find a solution? I have exactly the same scenario - Nextcloud server with 12Tb iSCSI storage (so I cannot make a snapshot because iSCSI storage doesn't support it). I would like to create same server with the small storage for upgrade tests, so I need to exclude 12Tb disk from configuration.
Cloning individual disks anf attaching it to new VM would be fine too .

 

[fiona]

Hi,

Hi!

Did you find a solution? I have exactly the same scenario - Nextcloud server with 12Tb iSCSI storage (so I cannot make a snapshot because iSCSI storage doesn't support it). I would like to create same server with the small storage for upgrade tests, so I need to exclude 12Tb disk from configuration.
Cloning individual disks anf attaching it to new VM would be fine too .

you can either:

• Shut down the VM, detach the large disk, make a clone (the detached disk won't be copied), re-attach the large disk, start the VM.
• Re-create a second VM with the same settings, but no disk. Then run qm set <ID of new VM> -<drive key> <target storage ID>:0,import-from=<volume ID of the old VM's disk>. This also works while the original VM is running.
  But it's hard to read, so here is a concrete example: qm set 356 -scsi0 dir:0,import-from=zfs:vm-104-disk-0 will clone the disk vm-104-disk-0 on the storage called zfs to a new disk on the storage called dir and attach it to the SCSI 0 bus for VM 356.

 

[Senin]

Hi,

you can either:

• Shut down the VM, detach the large disk, make a clone (the detached disk won't be copied), re-attach the large disk, start the VM.
• Re-create a second VM with the same settings, but no disk. Then run qm set <ID of new VM> -<drive key> <target storage ID>:0,import-from=<volume ID of the old VM's disk>. This also works while the original VM is running.
  But it's hard to read, so here is a concrete example: qm set 356 -scsi0 dir:0,import-from=zfs:vm-104-disk-0 will clone the disk vm-104-disk-0 on the storage called zfs to a new disk on the storage called dir and attach it to the SCSI 0 bus for VM 356.

Thanks, will try this on wekend.