Arcserve 11 problems

[L4ts]

Hi,

I am quite new to arcserve 11 and to begin with, we have Storagetek L20 library with 2 x LTO tape drives.
We backup over 50 servers nightly. Total comes to around 500GB so this requires us to use 3 tapes for each day.
I have configured arcserve by creating media pools with 3 tapes in each pool. All tapes in each pool have been named exactly the same (eg. Thursday_Week4).
Backups start working ok, but after a while I get a message saying 'Please mount media Thursday_Week4 or any media in scratch set of media pool [Thursday_Week4] or a blank media'. So it never touches the third tape.
What am I doing wrong?

 

[ACiDelic]

Is the third tape in the scratch set for the media pool being used by that job? The job will only use media that are blank (erased) or appear in the scratch set of the media pool specified.

Media are moved from the saved set to the scratch set after their retention time has passed. This takes place at the start of a job.

Perhaps your retention time is too high for the number of tapes you are using. A higher retention time means you will end up using more tapes. They don't become available for use for a longer period of time.