Re: Same issue exists for Domain Controllers running on AWS EC2
Do what I do, albeit in vmware, not aws. My backup script checks several things:
1) is this a paired system (yes, my DCs are all paired)
2) is this power-off-before-backup system. (yes, its the only /safe/ way to back up a DC)
If #1 is true and if #2 is true, I set a lock and use vmware to shut down the vm prior to the backup.
This keeps at least 1 domain controller online at all times (at each site) and even with the added shutdown/reboot delay, its still quicker than an online backup.
With the advent of dedupe storage arrays, and the caveat that you have to build all of your VMs from the same image, the total space to do incremental backups is, for my usage, neglIgable.
To answer another question posed above. I believe that Reduxio has the ability to revert a disk to a point in time. The issue becomes that you then have to have separate LUNs for each virtual machine.
Also, like has been pointed out above (and before, and forever after), if you haven't successully restored from a backup, you can't consider it a backup.