There have been a couple other threads with this error, but the solutions do not apply to this situation.
Event ID : 24
Reason: Backup started a fresh backup for volume '{00000000-0000-0000-0000-000000000000}' ('Esp') : [Reason: 'Volume size changed']. This may cause loss of older backup versions when backup completes.
Result: All backup copies are wiped.
Backup_Error Log Contents: Application backup *-----------------------------*
Server 2012 R2 Datacenter using Windows Server Backup to an iSCSI target which is 10TiB in size.
Server happily formats the 10TiB and has no complaints when backing up to the target. But it never uses all the space, the maximum we have seen is 4.7TiB.
The backup will generally complete around 14-16 copies, then the next backup will wipe all history stating the error above.
We have tried wiping the NAS and rebuilding the WSB Schedule with no change to the outcome.
I've not found any limits on the amount the server will backup or the target having a limit, so please enlighten me if there is such a limit.
Any one have any ideas/thoughts? Or do we simply need to abandon WSB and move to an alternative product.