Very Computer

In v1.X, I always patched drivers/scsi/st.c so that it did not do buffered IO,
so as to be able to control the tape block size. This is necessary for me as I
have to be able to import and export tapes at various blocking factors.

the 1.2.X st.c is very different and my first guess at the patches
failed miserably.

What is the way to turn on user controlled read/write block sizes for
scsi tape drives?

I use a WangDat 6200-HS.

Thanks -- Jason

Why can't you use mt?? I use mt all the time to set a zero block size
i.e.

   mt -f /dev/rmt0 setblk 0

Always seems to work for me when reading DAT tapes from non-Linux machines.

Cheers,
Steve.

--

Phone: +1 415 694 1729

: Why go to all this work?  Doesn't the "dd" program work for you?

SCSI Tape Drives can have there own Hardware blocking factor as well as
a software controlled one. Streaming tape drives do not do this, and only
look at the software blocking factor.  

I can see where this guy can run into problems.

I've seen how various other Unix's have handled this. Some use different
SCSI Tape device names while others can control this setup directly.

There is even a modified version of gnu tar floating around that has the
added option "physrecsz" that controls this.                      

The blocking factor that software apps use (dd, tar, etc) generally do not
refer to hardware blocking.

Just letting you know.                    

-Alan