I have BE2012 with LTO6, just moved from 2010. Below is my configuration:
My Settings:
I have 3 servers to back up (partial selections).
Differential backup runs 4 times a week and full backup once a week.
Differential backup only uses 1 tape per day (all 3 servers backup into 1 tape - around 200 to 400GB a day). Full backup uses 4 tapes. (8 TB data in total)
To allow all 3 servers to backup into one tape, I set the Media Set to "Append to media, overwrite if no appendable media is available"
Overwrite protection is set for 13 days for differential, and 4 weeks for full backup.
What Happened:
Last week i ran the full backup as usual, I was rewriting onto 4 used tapes (overwrite protection date has passed)
But later I found the backup job to be pending and all 4 of my tapes were full. This is odd since my total data is still a little below 8TB, but available media storage was around 9TB (before the full backup. now it shows 0). And my total data backed up was only 3TB, so there is 5TB to go but my tapes were full.
My Theory:
Why did this happen? I suspect the below:
The backup data was appended to the tapes instead of overwriting them (eventhough overwrite protection period is over)
Eventhough the Media Set was "Append to media, overwrite if no appendable media is available", as soon as the data was appended onto the tape, a new overwrite protection was set - another 4 weeks, so that's why all tapes are full and wann't overwritten.
Is my theory correct? Does it work that way?
Is there a way to set it up so that it overwrites all the tapes when the protection is over and then append data. Not append data then attempt overwrite.