Backups of VMs with enabled CBRC option fails when Linux backup proxies are used

Veeam Backup & Replication
10 and later
Last Modified:


Backups of VMs from ESXi hosts with the enabled Content Based Read Cache (CBRC) fail and you get the following errors in HTML report generated for a failed job:

Error    Hot-add of digest enabled disk not supported scsi0:1.
Error    Failed to attach disk 2000 to source Linux backup proxy <IP address> (<GUID>) (System.Exception)



This issue occurs if Linux proxy is selected in a backup job, when Veeam tries to hot-add a virtual disk to a VM which is deployed on the ESXi host with the CBRC option enabled.
Due to the VMware limitation, you cannot attach disks to VMs while they are powered-on.
Veeam Linux proxies have only one transport mode (hot-add) so far. That is not the case with regular Windows proxies. 

According to VMware documentation CBRC feature was introduced in vSphere 5.1, thus may affect all systems with this version and above.


To back up a VM with the enbaled CBRC option, you can try the following options:

More Information

Please be aware that we’re making changes which will restrict access to product updates for users without an active contract.


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