Hello,
I am experiencing an intermittent issue with the backup of a Exchange 2013 VM. Normally, backups take less than an hour on both the Host and Exchange VM. The host is backed up first, then the Exchange VM several hours later. After x amount of days a backup will fail and the VM's status changes to Running-Critical with the backup still in progress. At this point it appears to create a 4KB AVHD and becomes inaccessible until that is merged back in. Looking in the event logs I can't see anything in particular that is triggering it, though I may not be looking in the right place. I get event IDs 18190 and 18200 at 5 minute intervals on the host during this period. On the VM the last events are that the virtual disk service has stopped and that the Exchange databases have been frozen by VSS. This is at the time the host backup takes place.
If left to it's own devices it will recover, though this can take over 48 hours. The Exchange VM will then carry on as normal and complete's its backup as if nothing has happened.
Setup:
Windows 2012 R2 Host with 3 VM's.
VM 1: Windows 2012 R2 with Exchange 2013cu7
VM 2 & VM 3 have no issues.
Windows Server Backup runs nightly on Host and Exchange VM.
Both Host and VM OS's are fully up to date.
Has anyone else had a similar issue? Or can point me in the right direction?