Proxmox - backing up the domain controller with FSMO roles

[vjk]

Hi All,

Could someone tell me what is the efficient way to backup DC VM with FSMO roles? Is it any logical and safe workaround? Cause when I use Stop Mode my local network is dead for couple of seconds. Should i transfer FSMO roles to a diffrent DC during backup? And if yes then during backup FSMO roles will not be saved as well.

Thanks,

 

[ness1602]

Why do you use stop,can't you use suspend?

 

[vjk]

Hi Ness, thank you for quick reply.

If I'm not wrong:



Basically that one VM currently is backup using snapshot but i need to be sure if that server somehow will fail that i can fully restore that snapshot on fresh proxmox installation and everything will work perfectly cause snaps - software failures and backups - hw failures as far i know.

If I can safely restore that VM from snap then all good, i just want to be sure that there will be no issues during process.

Thanks,

 

[aaron]

Why not the snapshot mode? For VM backups, the snapshot mode does not rely on any snapshot functionality of the underlying storage. It is using the virtualization layer to make sure that each part fo the disk is backed up as it was when the backup started. This means that if the VM wants to write to parts of the disk that the backup job hasn't saved yet, that write operation will be temporarily blocked. The backup will then backup that part of the disk out of order before the write operation of the VM can continue.

If the VM has the guest agent installed and if it is enabled in the VM options, the gest agent will get a fsfreeze command (that you can see in the backup task log). The guest agent inside Windows will then trigger VSS to make sure that things are written down to disk before the backup starts.

 

[vjk]

Hi Aaron,

Thanks for response!

So if I understood well - snapshot can be safely put on the same level as stop mode backups? There will be no issues to restore snapshots to fresh proxmox installation, in the scenario that most critical server will fail?

Thank you,

 

[aaron]

So if I understood well - snapshot can be safely put on the same level as stop mode backups? There will be no issues to restore snapshots to fresh proxmox installation, in the scenario that most critical server will fail?

Yes. The stop mode works very similar to the snapshot mode. If you test it out, you will see that the VM will start right away. By shutting down the VM we can be even more sure, that everything has been written down to disk before we start the backup.

 

[vjk]

Thanks all of you guys for your reponse, now everything seems to be more clarified!