Storage vMotion and Change block Tracking are now friends

A lot of readers may be aware that storage vMotion is a awesome feature that I love.  It had one nasty side effect it reset change block tracking (CBT).  This is a huge problem for any backup product that uses CBT (Veeam, anything else that does an image level backup).   It means that after a storage vMotion you now have to do a full backup.  It’s painful and wasteful.   It means that most enterprise environments refuse to use Automation storage DRS moves (one of my favorite features) because of it’s impact on backups.    Well the pain is now over… and has been for a while I just missed it :).   If you look at the release notes for ESXi 5.5 U2 you will find the following note:


  • Changed Block Tracking is reset by storage vMotion
    Performing storage vMotion operation on vSphere 5.x resets Change Block Tracking(CBT).
    For more information, see KB 2048201

    This issue is resolved in this release.


I wish I told us more about the change or why it is no longer reset but I guess I’ll accept it as is.   The previous work around was don’t use storage vMotion or do a full backup after… which is not a work around but an effect.  Either way enjoy moving the world again.

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