How to – reset CBT on multiple virtual machines using PowerCLI

There is a VMware KB article available that describes the necessary steps very well. But sometimes a picture is worth a thousand words – so here a detailed description with some screenshots. The advantage of this script is, that there is no need for a downtime of the affected virtual machines.

How to reset CBT for multiple VMs running on the same ESXi host:

Command: Set-ExecutionPolicy Bypass

reset_cbt_0

  • start the downloaded script:

Command: .\CBT-Reset.ps1

you can now cancel the script pressing “control” + “c” or you specify the FQDN (or IP address) of the host whose VMs you want to reset CBT.

cbt reset powercli

  • a window opens where you can specify the root credentials to the ESXi host:

specify credentials

The script will now list all VMs where CBT can be reset and those, where a CBT reset is not possible. There are two reasons why a CBT reset is not possible: the VM is powered off or an open snapshot exists.

You can now cancel the script pressing “control” + “c” or you press any key to start the CBT reset of the applicable VMs. Depending on the number of VMs the script will run some minutes – do not cancel it once it is executed.

cbt_reset_list_vm

Please note, that the first backup after resetting CBT will be a Full Backup. This backup will take a longer time to finish and of course it is necessary to backup more data than performing an incremental backup!

Leave a Comment

Your email address will not be published.