BE2010 AVVI, Weekly/Daily Templates plus Manual Full Backups

[Sublaner]

Hi,

We perform backups of VMware 4.x virtual machines using Weekly Full / Daily Differential templates created by policy, GRT enabled. VMs are Windows 2008, Backup Exec is 2010 R3. It works pretty well. (We are upgrading, but need to support this setup at 30+ discreet sites during a s-l-o-w rollout.) We also manually perform quarterly "off-site" AVVI backups to USB drives.

I got to wondering, does the Full backup we perform to the USB drives interfere with cbt for the policy-based backups? In other words, do the Differential backups run the rest of the week link back to the manual Full VM backup, or to the policy-based Full that ran before it over the weekend (do I need to re-run the template-based full backup after the manual backup)? A "Full-Copy" backup should not affect change tracking, but this does not seem to apply to VMware backups.

In a related vein, if that weekly Full fails or gets cancelled the Differentials still run successfully. We figure that was okay because "the differentials would work with the last good full backup". My reading lately suggests otherwise, and that I would need to complete a good full backup for later differentials to be usable. Which is the case?

Thanks for all your comments.

[pkh · Accepted solution]

A differential backup backs up all the changes and additions since the LAST full backup, regardless of whether the last full backup is part of the policy or a stand-alone run.  So if you run your backup to the USB drive after the full backup of the policy, then subsequent differential backups will use the backup to the USB drive as the baseline.

If your full backup fails, then you need to rerun it.  Otherwise, your subsequent differential backups are useless because there is no good baseline.

[Sublaner]

I implied but failed to specify that the "Backup Method for Files" selected on the GENERAL tab was "Full-Copy the files" for the occasional USB jobs. To test this I ran the offsite job, ran the policy Daily Diff job, disconnected the USB rive, and restored some files from the Differential. To my surprise the files restored fine, and timestamps on the B2D files and IMG folders show that the DD looked back past the Full Offsite job to the previous successful scheduled Weekly Full backup. The restored files existed in the WF and were not changed for the DD. Undocumented feature of the AVVI?