aeccles wrote:1) What makes this possible? I've had reboots occur while jobs were running before and the jobs ended (failed.)
Veeam B&R is an image-based solution that leverages VM snapshots to backup VMs. Basically, at the moment when backup starts, VM snapshot is created and VM data is retrieved from this snapshot. After the backup snapshot is committed to the parent virtual disk.
aeccles wrote:2) Will this backup be reliable, especially since updates were installed in the middle of it? I'm guessing/hoping that VSS will only transfer the data as it was when the job started?
The backup will be reliable, however, it should finish first, which in case of Exchange running from snapshot for several days could take forever
. Have you considered to use backup seeding
option for remote backup scenario?