ESXi 5.5 Update 2: Storage vMotion no longer resets CBT!

Just noticed that the behaviour of Storage vMotion with CBT (changed block tracking) has changed since ESXi 5.5 Update 2.

Using vSphere prior to version 5.5 U2, a Storage vMotion resets CBT.

This is a problem, because backup products like eg. VMware Data Recovery (VDR), vSphere Data Protecion (VDP), Veeam or IBM TSM are using CBT to perform incremental backups.

As a result, after moving a virtual machine via Storage VMotion to another LUN, the backup software performes a full backup instead of an incremental.

With ESXi 5.5 Update 2 this issue is resolved, as you can see in the release notes of vSphere 5.5 Update 2:


If you want to read more about this, take a look at KB 2048201:
Changed Block Tracking is reset after a storage vMotion operation in vSphere 5.x

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