Accelerator forced rescan for virtual machines (schedule attribute)
The accelerator for virtual machines uses Changed Block Tracking (CBT) technology from VMware to identify changed blocks. NetBackup requires the changed blocks when it creates a full virtual machine (synthesized) image. NetBackup is therefore dependent on VMware CBT for correctly identifying changed blocks. To protect against any potential omissions by underlying VMware CBT using timestamps, the option conducts the backup by collecting all in-use blocks as reported by VMware CBT.
When Accelerator forced rescan is used, all the data on the virtual machine is backed up. This backup is similar to the first Accelerator backup for a policy. For the forced rescan job, the optimization percentage for Accelerator is 0. The duration of the backup is similar to a non-Accelerator full backup.
Note:
Under normal operations, an Accelerator forced rescan schedule is not necessary for VMware backups. It can be used to enforce a new baseline backup in case VMware CBT issues are discovered. Engaging with Cohesity Support is recommended in such situations.
Accelerator forced rescan is unavailable if the option on the Attributes tab is not selected.