We have recently started using BE 2012 with a quantum value loader as the hardware, we are using a full backup / incremental back up method.
We are doing a full backup of all servers over the weekend, this takes 4 tapes so we have partitioned the valueloader with slots 5 - 8 for the full backups over the weekend and then use 1 - 4 for the incremental backups Mon - Thurs...
The issue we have is the backups for whatever reason will not use slot 5, the first backup that runs is the file server, this has approx 400GB data and with us only having a sdlt 320 spans 3 tapes, this works fine and does this OK, the second server backs up OK which leaves approx 30GB free on tape 8, the third backup backs up 32.2gb ( same amount each time even though the amount of the previous backups are different ) then it fails, giving an error that the tape drive needs cleaning or the tape needs replacing ( both of which we have done )and also there are 2 other servers after this one, that fails with an error that they can't find any appendable media, which means it's not trying to use tape 5, If I manually run the failed job it uses tape 5 and completes the backup job no problems.
I've checked all the settings of slot 5 and the backup job that initially fails but can't see anything that could cause this.
Has anyone got any ideas what could be causing this?