Backing up a CBT enabled virtual machine in ESXi 6.0.x returns incorrect changed sectors

BUG
This is a known issue affecting ESXi 6.0 and ESXi 6.0 Update 1.
Currently, there is no resolution. VMware have identified the root cause of this issue.
To work around the issue, choose one of these options:

Veeam users have one more option, and that is to disable the use of CBT data in the advanced job settings. Your backups and replicas will remain incremental, but they will take longer, because the job will need to read the entire source disk to determine the changes. Disabling CBT is essential – otherwise, even Active Full backup may contain corruption, because CBT data is used there too to determine and skip zeroed regions of virtual disks. On the other hand, disabling CBT is sufficient to both prevent and remediate the issue, because this will make jobs physically compare latest state of disk in backup or replica with its actual state, and transfer any non-matching blocks over as a part of incremental backup (along with actually changed blocks), thus fixing any corruption that may already be in place.

Sources: VMwarevinfrastructure.itup2v.nl

 

 

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