Max blocksize for LTO-4 tape unit

Hello all,
We were using an IBM 3580 LTO-4 unit with SLES11 sp1 and used tar with a -b option of 16384 to speed up the transfer of 400Gb to tape.
For access to the drive we had the IBM lin-tape driver installed.
After upgrading to SLES11 SP2 the -b option of tar is maximized to 2048. All higher values give an error
The speed of the transfer to tape is acceptable but we can’t read our old tapes.
We did install the latest lin_tape driver
Does anyone know where the maximum block-size of a SCSI attached tape unit is determined.

Thanks in advance


It appears that in the past few days you have not received a response to your
posting. That concerns us, and has triggered this automated reply.

Has your issue been resolved? If not, you might try one of the following options:

Be sure to read the forum FAQ about what to expect in the way of responses:

If this is a reply to a duplicate posting, please ignore and accept our apologies
and rest assured we will issue a stern reprimand to our posting bot.

Good luck!

Your SUSE Forums Team

Finally found a solution.
The problem was caused by the mptsas module.
Changed to CentOs 6. This mptsas module accepts the parameter “mpt_loadtime_max_sectors=16394”.
Now the tapes can be read and written with 8M blocks again.

Thanks for reporting back.

Kim - 10/16/2012 9:46:32 AM