SCSI Tape Device Handling of Recovered Errors in 2.0.x kernels

Evan Harris (eharris@puremagic.com)
Sun, 8 Nov 1998 20:44:55 -0600 (CST)


I am curious as to why after writing to a tape that I _know_ has bad spots
using dd (reported by the same drive and tape by other backup programs
under other OS's), then issue a scsi request sense (using mt status), the
drive always reports 0 for the soft error count.

I believe that in most (if not all) devices, the soft error counters are
reset whenver a request sense is done. So this leads me to think that the
kernel is doing request sense calls in the normal handling of the tape
device.

My question is this: How can I read the recovered error counts for a
device without doing all the lowlevel handling of the device? Is there
any facility in the kernel for finding this out? So that I can read the
device error count, do a tar, read the device error count again, and
subtract to find the number of soft errors that occurred during the tar?

Any info or pointers would be appreciated.

Evan

--
| Evan Harris - Consultant, Harris Enterprises - eharris@puremagic.com
|
| Custom Solutions for your Software, Networking, and Telephony Needs

- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/