Data corruption may be observed for a VMware Virtual machine backup which has a ReFS volume configured on a dynamic disk.

Problem

Data corruption may be observed for a VMware Virtual machine backup which has a ReFS volume configured on a dynamic disk.

Error Message

Restored Virtual Machine REFS volumes shows as RAW Disks.

Cause

Backup Exec performs disk optimization during the Virtual Machine (VM) Full backups. During VM backup, it traverses through the volume metadata information and finds the disk data blocks which need to be backed up.

If the volume inside the Virtual machine is a ReFS, Backup Exec returns the incomplete list of data blocks for backup. The backup job is reported as successful but the backed up data from ReFS volume is incomplete. The restore job completes successful but not all blocks of the  ReFS volume are restored.

This Issue is seen for both GRT or Non-GRT backups of Virtual Machines which has a volume configured as ReFS on dynamic disks.

Note:
A Virtual Machine with Dynamic Disk configured as ReFS experiences this Issue.
A Virtual Machine with Basic Disk configured with ReFS volumes are not affected by this issue.

Solution
 

Workaround: 

Backup Exec 21.1 and earlier are affected by this Issue. If this is the scenario for the Backups, then it is recommended to test a restore to confirm the behavior.

To avoid the data loss situation configure the Backup job using the traditional method and Backup the Virtual Machine as an Agent based backup.

Note: The affected Backup Sets for this scenario cannot be restored. Hence the workaround should be put in place as soon as possible.

This Issue is fixed as part of Backup Exec 21.2 version.
Veritas recommends an upgrade to BE21.2 when it is available. 
The Patch can be downloaded from Veritas Download Center when it is available.