I came across the above error message for Veeam Cloud Connect tenant backup jobs. I have previously encountered the error for a single backup and then was resolved upon the next scheduled backup, so I simply point it down to a network issue at the time of backup.Upon raising the issue with veeam support and they provided the following solution that is part of KB2282. The issue presented itself that all customer tenant backup copy jobs were displaying the error message “waiting for backup infrastructure resources availability”. Below is the content of veeam KB to fix the issue:
KB ID: 2282
Product: Veeam Backup & Replication
Version: 9.5.x and later
Cause:
Veeam Backup Service stores information about free space on each extent in cache. When Scale-out Backup Repository resource is assigned to a certain task, number in cache is subtracted with estimated size of task and is not updated with real free space while there is at least one task going to extent. Estimates may be not precise and difference between real and cached free space may grow.
Solution:
Update 2 for Veeam Backup & Replication introduces new space update logic. When extent is assigned to a new task, service cache updates free space information with the real one and subtracts it with estimated sizes of all the tasks currently going to this extent.
You can switch to new logic by creating the following registry key:
Key: HKLM\SOFTWARE\Veeam\Veeam Backup and Replication\SobrForceExtentSpaceUpdate
Type: DWORD
Default Value: 0 (Disabled)
and setting value to 1 (Enabled).