is there any quicker way to erase a tape?
my first tape drive doing this at the beginning of each backup works ok, it takes about 45 minutes but we have the time.

the current drive Im trying to setup dlt IV: 40/80gb) is taking hours.. im not sure its hung or what .. there must be some sort of quick erase??!? thanks so much for any tips. have no problems running backups and restores. it just seems to run and run.. i left it for 3 hours once.. spin and spin... thanks!

HP's DLT drives aren't great performers.. I had one and finally replaced it with a Sony DDS3/260GB, which is *much* faster. HP had the balls to say "You should be happy if it stores just 40GB." in those exact words when we called for support when the bloody drive locked into some sort of irreversible 45GB storage limit on 80GB tapes. We hung up and trashed the drive.. which right now is kinda a problem because I can't really help you that much that way.
My guess is either you request a full format or the drive itself is interpreting the command as a full format command. The DLT is a horrible machine when it comes to formatting/searching/rewinding, it's almost as if it's doing the same action twice or more just to annoy you. If you still hear that awful whingy intermitted scratching/rattling, the drive is still working to complete the requested task. I believe the average transfer rate is about 12mb/s for a SCSI DLT drive, if memory serves.

thanks for your help. well you appear to be right as my first "scsi" tape drive on the last server was actually one of those sony ait IDE drives and its way way faster than this real scsi drive. its one of the ones that came with an old dell server.

thanks for trying to help but i think i have a workaround, it appears that every backup (i'm using cpio) just startes writing at the curent tape position, and it LOOKS like it just overwrites everything thats there. i just tested doing a backup (using /dev/st0 knowing it always rewinds the tape). i listed the tape contents to make sure it backed up, then i backup up another directory and listed the tape, only the most recent backup is showing. SO>>> ill test a bit more but this looks like the behavior im looking for so i wont need to erase the tape (with a separate command).

i think the dlt is 3mbps transfer rate and up to 6 with compression.

thanks!

That's rather poor even for a DLT.. might want to try to see if you can find a newer firmware for your drive and see if that helps the transfer rate a little.
If your tests prove the behaviour is favorable you're set, it will save a lot of time if you don't have to format in advance. Good luck