CBT issue

[ferrus]

We have a job with several file servers in. They've worked fine for years, but recently a 6TB drive on one server started reading the whole disk, despite showing (CBT) in the job log.
After five or six full backups of the disk, the CBT started working again.

Almost straight after that worked however, another VM in the job has the same issue - with a 10TB disk. It has done full disks reads several times now, despite showing CBT.

My question is - is it worth putting a support call in, or should I go straight to resetting the CTK/CBT flag in VMware?
Each day it's re-reading the 10TB disks, is another day we're not getting backups of the other VMs in the job, so I'd go for the quickest fix if that's the likeliest solution from Veeam support.

[HannesK]

Hello,
it takes around 6h to back up 10 TB without CBT at a read rate of 400MByte/s (which is the minimum speed I assume for environments with that size of VMs as not stated elsewhere). So resetting is probably faster than opening a case.

If you want to know the reason, then I recommend opening a case.

Best regards,
Hannes

[ferrus]

Thanks - I assumed that, I'll reset the CBT on the next job run.

We don't get anywhere near those speeds unfortunately, which I'm convinced is down to the speed of our SAN rather than anything Veeam related.
Hence why we're paying such a big penalty for repeated full disk reads.