When backing-up a Microsoft Exchange 2010-2012 VM via vRanger (whether using guest quiescing or not), the snapshot files created before the backup begins grow to extreme size in a very short time (even several GB per minute). This makes it almost impossible to delete the snapshot at the end of the backup, or even to complete a backup before the datastore fills-up with snapshot data.
Microsoft DAG (Database Availability Group) may be enabled on the Exchange Message Store. This technology works from within the Microsoft OS to replicate the Exchange data "real-time" to another offline Exchange Message Store as a Disaster Recovery (DR) hedge. This mechanism is constantly re-arranging disk pointers/blocks on the VMFS disk of the Exchange VM, and causes uncontrolled snapshot growth:
Disable DAG when running Exchange on a VM (as it is not supported). There is no other planned fix from VMWare/Microsoft to allow this function to be supported.
Use of the vRanger Physical client has allowed DAG members to have a successfull backup. This bypasses the need for a VMware snapshot and uses only the Windows Volume Shadow copy service.
