my 36/72 tape is detected as 20/40

[Russ Foster]

I have a HP DAT 72gb SCSI drive connected to an HP machine running Windows 2003 SBS and using Veritas Backup Exec 9.1

Several of my 36/72 GB tapes are detected as 20/40 GB tapes...and...consequently, my backups fail.

My backups average 50 GB and my compression averages 1.5:1 ... which is fine for a 36/72 , but not a 20/40 tape.

Yes, the tapes are 36/72 GB ... blue and all.

If anyone has any ideas, please help.

Thanks!

-r

[CA713937]

Russ,

I believe the tape capacity (and format) detection for DDS is based on a set of holes on the tape cartridge, which the drive senses. There may be a problem with sensing those holes.

Where are you seeing the 20/40GB capacity reported for the 72GB tapes?

HP L&TT should report the loaded tape capacity on the identity tab (and in the support ticket).

[Russ Foster]

The 20 GB is reported that way in BackUp Exec.

Not only are the labeled wrong, but they actually stop backing up data around 30 GB (which is right since I am averaging 1.5:1 compression).

15 of my 23 tapes are (incorrectly) labeled as 20 GB tapes (again, according to Backup Exec).

I wonder if there is a way to reformat the tapes...?

But how did 15 tapes get this way in the first place?

-r

[CA713937]

As I mentioned before, I believe it is the holes on the bottom of the tape (there are unique binary patterns for each tape format, and for the cleaning tape) that determine the (native) tape capacity.

The Dat72 drive supports Dat72, dds-4, and dds-3 tape formats. My guess is the drive is incorectly detecting some dat-72 tapes as dds-4 (20/40GB).