Unexpected full files to tape job

[pufferdude]

Something weird happened last night that I cannot explain. I have a File To Tape job of our NAS which currently holds about 56TB of files. Because it's impractical to make regular full backups to LTO8 tape with that much data, my process is to do a full on one set of tapes, then do ONLY daily incrementals for 3mo, then remove that entire backup set and replace it with one that's been offline, mark those tapes free, do a new full (which takes almost 3 days) and then do incrementals for 3mo... lather, rinse, repeat. That way I always have a worst-case 3mo old offline backup of the entire NAS.

Anyway, this has always worked fine until last night when the job kicked off and it apparently decided to back up EVERY FILE on the NAS (effectively, a new Full) again. My first thought was, of course, "ransomware!!" but on the NAS itself everything looks normal... all files are intact with expected modified dates in the past, no files have weird extensions, they can all be opened and appear perfectly normal. Absolutely nothing on the NAS itself seems out of place... it's just as if Veeam decided to do a Full instead of Incremental job.

Anyone ever see something like this, or further steps to identify what's happened? (I of course checked the job and NO, it is not configured to do automatic fulls... just incrementals). At this point I'm going to let the new "full" complete before proceeding with patching Veeam to that latest update, etc. Currently I'm running 11.0.1.1261 P202111211.

One additional (maybe related?) data point is that this is a newly-migrated (about a month ago?) Veeam server... but it's been doing the daily file to tape incrementals just fine post-migration.

[HannesK]

Hello,
what did support say about the reasons after investigating the logs?

Best regards,
Hannes