One of the most useful recoveries you can do in Avamar, NetWorker or PowerProtect Data Manager is the changed block tracking recovery.
Within VMware, a changed block tracking (CBT) recovery is what you do when a virtual machine has been damaged or corrupted. Either there’s no option to fix it, or the time it would take to somehow dive into the operating system and repair the damage is too much. You.Just.Need.It.Back.
If you’re recovering a virtual machine to an entirely new VM, you’re going to have to read the entire VM from storage. So a 1TB virtual machine requires 1TB of data being read from your protection storage.
On the other hand, a CBT recovery compares the differences between the VM’s blocks on disk now, and what’s stored in the backup you’ve selected. The blocks that are the same between the copy on disk and the protection storage copy aren’t recovered. Why waste time? Instead, we only need to recover data for blocks that have changed since the backup.
So if you’ve got a 1TB virtual machine that had some patching done on it and it now won’t boot, or someone has done a ahem boo-boo within the VM, it could be that there’s only hundreds of megabytes that have changed since the backup. That can be a huge difference in the time it takes to complete.
In the video below, I’ll take you through the CBT recovery process.
You can click the caption above to go through to the YouTube video directly, if you’d like.
Hey, before you go – don’t forget that the second edition of Data Protection: Ensuring Data Availability has been released. Here’s a link to the publisher site.