Move VMs between or to new backup job

[GabesVirtualWorld]

Hi
Still fighting the Hyper-V 2019 CBT bug. Trying to backup all VMs without CBT, but we don't want to lose the chain and double our backup storage needed. So I'm looking into ways to transfer the VMs to jobs without CBT, but I can't move them all at once because I have to keep an eye on the impact of the backup window. We have a very narrow window in which we are allowed to operate.

I have one backup job containing 100 VMs. The job is using CBT and the repository (Pure-C storage with dedupe) has "Use per-VM backup files" enabled. From other posts here on the forum I read that I could create a NEW job with CBT disabled, import a VM backup chain into that job. Is this correct? Would that NOT cost me a complete new backup chain in storage and an old chain I need to keep for a few years? Maybe only a one time full backup extra?

How could I do this for 100 VMs? Would I have to create 100 jobs then because I can't import a VM to an existing job if I'm correct.

If this indeed would mean 100 jobs, what would this do for the running time of the backups. All the hosts are 2 socket, each socket 10 cores. Does it make a lot of difference having one job with 100VMs or 100 jobs with 1 VM?

Regards
Gabrie

[PetrM]

Hi Gabrie,

You can create a new job with CBT disabled and map this job to an existing chain, you may look under "Map backup" on this page. Once mapping is done, job continues to run according to schedule in the corresponding mode whether it is full or incremental. However, I recommend you to pass this scenario using a smaller job with just a few test VMs before you do the same thing with the main job having 100 VMs.

Also, it's not clear why you cannot just disable CBT for the main job?

Thanks!

[GabesVirtualWorld]

Hi,
When disabling CBT for the main job, I'm going to have a lot of VMs at once that are no longer using CBT and I might not make my backup window. By doing this granularly I hope to stay in control.

[PetrM]

Hi Gabrie,

Maybe I misunderstood the initial request. You cannot do it gradually and map multiple different jobs to the same backup. The mapping can be done only once for the whole job that contains necessary VMs. Could you please also provide a link to a post where you read that such a gradual mapping is possible so that we can be sure that we're on the same page?

Thanks!

[GabesVirtualWorld]

Ah... ok. To cut it up in smaller steps:
- Main job with 100VMs
- move 1 VM to a new job and import this one VM into this job and not lose the chain.

That should work right?

Now the next step, is what probably won't work reading your comment:
- move 2nd VM to the new job and import the chain. In the end having 2 VMs in that job.

Would another option be to create 100 new jobs, each containing a single VM? I understand that importing the VBM file will cause the new job to THINK it has to backup all those VMs, but we would then have to remove those VMs except for the one.

Or maybe we could do it in steps of 10 VMs? Have 10 new jobs, each holding 10 VMs.

The post I'm referring to is this one:
veeam-backup-replication-f2/feature-req ... 68246.html
With the reply "by foggy » Jul 19, 2020 10:09 pm"

[PetrM]

Foggy's comment is about one-time mapping procedure which must work without issues.

That should work right?

Yes, you can map a new backup job to an existing backup.

Now the next step, is what probably won't work

It will not work because there is no option to import an individual chain but the whole backup containing 100 VMs only.

Would another option be to create 100 new jobs, each containing a single VM?

No, it's not an option. A job can use only one backup, therefore 100 jobs must have 100 backups and there is no way to split the backup produced by the main job on 100 different backups.

Or maybe we could do it in steps of 10 VMs? Have 10 new jobs, each holding 10 VMs.

It's not an option neither and the reason is the same as the one outlined above.

What about to extend backup window temporarily and perhaps run the main job with disabled CBT on weekend?

Thanks!