Backup copy from a incomplete back chain

[danielchung]

I have a offsite backup job which is forward incremental, 10 restore points and synthetic full on Friday. Recently the job failed due to instability in WAN link. The backup chain still have a full backup in it, the latest full however was incomplete.

I wanted to make use of "resume" feature in backup copy to overcome the issue on the WAN link. I tried to use the existing backup chain as source to generate a full backup, then thought to copy from remote site base on this full backup. But it failed with "Unable to resume copy because the required restore point is missing".

Is there any way to use this backup chain in backup copy job so that I don't have to copy from remote site from the beginning?

[foggy]

Daniel, if I understand your correctly, you were trying to seed the offsite backup copy job using the backup created by the local backup copy job, instead of using your current offsite regular backup job, right? Which of the backup copy jobs produced the above error?

[danielchung]

Foggy, I wanted to create a new set of offsite backup that will be used in backup copy job. I have regular offsite backup in offsite repository containing an incomplete backup of last full backup, as well as some previous complete full and incremental. I need to create a new full backup first, so I tried to create a backup copy job using my current regular offsite backup as source, but it produced the error.

[foggy]

Ok, not sure I understand the whole scenario behind, but the fact is that backup copy job always copies the latest VM state, so it retrieves blocks from the most recent restore point within the interval. In your case the restore point containing required blocks is corrupt and the job fails.

[Vitaliy S.]

Actually if you already have backup files of the VMs you want to sync with the offsite location this should be enough. See Alexander's explanation in the second paragraph of this post > Seeding offsite backup files for a Backup Copy Job

[danielchung]

Actually I was in that thread you mentioned. What I was trying to do is to create a single vbk from existing offsite backup at remote site by using backup copy job, once the vbk ready, then start backup copy from local site to increment this vbk at remote site. However, I got error in the first step, and wondered it was because the most recent restore point in the backup was incomplete. I thought the backup copy job would use the last success restore point to generate a vbk even the most recent restore point was incomplete, but seems that's not the case.

Maybe I revise the question to "Is it possible to generate a vbk from existing backup chain like this":

Full, status OK (the oldest )
Increment, status OK
Increment, status OK
Increment, status OK
Increment, status OK
Full, status OK
Increment, status OK
Increment, status OK
Full, status Incomplete (the most recent)

Sorry I might not have explained the situation clearly. Just looking for any method to avoid transferring the whole full backup data over the slow and unstable link again.

[foggy]

While it seems not possible to generate new VBK, probably this is not even required. What Vitaliy was referring to is that with backup chain already available at remote site, backup copy job will populate its WAN accelerator cache with OS data from this backup without actually mapping it to it. This will result in much less traffic over the unstable link.