How to erase tapes from a command line?

To erase tapes from a command line use tapetest.exe. It is a command line utility found in the ARCserve home directory. First use the -y parameter to get the Device Number of the tape drive. The Tape Engine has to be running to use Tapetest.

Here is a sample of tapetest -y.
C:\Program Files\ComputerAssociates\ARCserve>tapetest -y
DeviceNo Board Bus ScsiID LUN DeviceType InquiryData
-----------------------------------------------------------
0 0 0 0 0 2 (HDD) Maxtor 90650U2 MA54
1 0 0 1 0 2 (HDD) Maxtor 82100A4 CA8X
2 1 0 0 0 258(CDROM) NEC CD-ROM DRIVE:28B3.05
3 1 0 1 0 5 (TAPE) Seagate STT8000A 5.02
-----------------------------------------------------------

In this case the tape drive is Device Number 3.

Now to erase a tape it done like this.
C:\Program Files\ComputerAssociates\ARCserve>tapetest -z -m2 -d3
*****************************************************************
* ERASE TAPE *
*****************************************************************
Erasing Device : 3 Mode: 2

TapeErase SUCCESS

Add the command to a backup as a Pre command and the tape will automaticaly be erased prior to backup.