One of the most common backup issue I see when backing up VM
images is that change block tracking in not set. If it is not Avamar has to parse the entire
vmdk file to find the changes causing the backups to run long, it puts a large
load on the server and storage during the process. Using change block tracking greatly improves
VM image backup time. To ensure Avamar is using the feature, you must both
check the option when you add the client as one that will be baked up and
ensure it is turned on in VMware.
You can validate it's enabled on your VMs by using
java -jar proxycp.jar --cbtstatus | grep -E "VM Name|CBT"
add the --vm VMname flag to check a single server
If you would like to try and enable it on all VMs:
java -jar proxycp.jar --cbtstatus --enablecbt
This will cause Avamar to attempt to enable it on all VMs it
has registered. If the VMware hardware level is too low to support CBT it will
just error out in VMware.