Hi all!

Is there any way to tell about a scsi tape, that how many times was is written? I am thinking about replace my DDS4 tapes, as it is recommended to do so after 100 rewrites. I want to know if the tapes have reached this number.

Thx: Krisztian

To my knowledge no tapes record how many times they've been overwritten. However, depending on the backup schedule that you use with those tapes, if you know when they were purchased you can guesstimate approx how many times they've been rewritten. For example if they tapes are rewritten daily, and you bought them at the beginning of the year, then they're coming up fast on that 100 mark. Similarly, if they're used on a weekly basis and they're about 2 years old, they're due.

If you're unsure, replace them. If you have doubts or can't trust your backups, why take the risk. Good luck with it and welcome to LQ -- J.W.

You either keep records yourself or you have a software package that does that for you.

If you have a script that does your backups, issue "mt -f /dev/nst0 status" (or whatever tape device you're using) just before doing the backup and again when it's done. Then grep for the string "Soft error count since last status=N" (well, only search for the string up to the "=") in the result of the second "mt status" command. If you see that N is non-zero, that's probably a good-enough indicator that the backup is questionable and it's time to replace the tape.

It's good that you are thinking of monitoring that. My backup script was warning me about errors that occurred during the session. Next thing I know I'm ejecting the tape (manually which was odd since the script does a "mt rewoffl" once the backup is done) and part of it is hanging outside the cartridge and flapping in the breeze. Used that cartridge one time too many.