vsan, backup proxies, CBT

[tntteam]

Hello,

Could someone give me some clarifications about vsan - veeam - cbt party ?

According to https://helpcenter.veeam.com/docs/backu ... l?ver=95u4

CBT is disabled if you back up proxies that use Virtual appliance (HotAdd) mode to process VM data.

According to https://www.veeam.com/blog/vmware-backu ... ation.html

Hot Add transport mode
Disables CBT on backup proxy server.

According to https://www.veeam.com/kb2273

Configure virtual proxies to make use of Hotadd. This can be any supported Windows server deployed as a VM on a host that has access to the VSAN cluster; the Proxy VM's disks should also be located on the protected VSAN cluster.

We tested with 2 veeam proxies, proxy-1 located on iscsi datastore (so not vsan), proxy-2 located on vsan datastore.

With proxy-1, backup transport mode used was NBD and CBT shown as active
With proxy-2, backup transport mode used was hot-add and CBT show as active

So, are doc and blog wrong ? What am I missing ?

Thanks !

[Sturniolo]

Hello Tntteam,

"CBT is disabled if you back up proxies that use Virtual appliance (HotAdd) mode to process VM data."

This statement is referring to the backup of the actual proxy itself. Not all VMs. So if you backup the proxy and its set to use HotAdd as a transport mode, CBT will not be used. CBT will be disabled as a backup method for that proxy VM. All other VMs being backed up via HotAdd will be able to use CBT.

Thanks... Any other questions on it just let me know!

[tntteam]

Hi!

Thanks for the clarification. Perfect

[Andreas Neufert]

The reason for this is it do not make sense to track the changes for all the VM disks that you attach temporarly to the proxy (hotadd processing).