This is from someone else:
Batch File to Erase tape before job runs:
I wrote a little batch file called taperase.bat which I run manually to erase all our 8 drives prior to backup. You use the TAPETEST utility within the ARCserve directory. Just change to ARCSERVE/ARCSERVEIT and look for TAPETEST.EXE. If it's there, enter TAPETEST at the command prompt and you'll see all the switches.
Basically, the command I use is:
TAPETEST -z -m2 -d5
TAPETEST -z -m2 -d6
And repeat down to -d12
This does a quick erase plus on devices 5 thru 12.
You need to go to the Device Screen to find out the device IDs. Note that if you have an array, you need to specify each device separately and will have to encapsulate the multiple TAPETEST commands into a batch file which you can set to kick off prior to the backup job in the Pre/Post options. Bit of a pain but it should be possible.
We run weekend backups as well on Fri, Sat and Sun nights, which is why we use the manual utility - it only gets run when we're here to change the tapes! Fri, Sat and Sun