From: jsilva@netcom.com (John P. Silva) Subject: Re: "SCSI host 0 timed out: Aborting command." ??? Date: Wed, 21 Apr 1993 03:53:33 GMT
Eric Youngdale (eric@tantalus.nrl.navy.mil) wrote:
:>In article <1993Apr19.041254.25509@uc.msc.edu> mfrankow@piper.hamline.edu (Mike Frankowski) writes:
:>>Vladimir Vukicevic (vladimir@intrepid.intrepid.com) wrote:
:>>: I have been getting these messages frequently lately. What do they mean?
:>>: How can they be fixed? I am using SLS, kernel 0.99p8 on a 486DX/50 with
:>>: an AHA-1542B SCSI controller and a ~500MB SCSI disk.
:>>
:>>: - Vladimir
:>>: - vladimir@intrepid.com
:>>
:>>I have a 1542c, and if the bios is turned on, I get the same error, with
:>>the bios shut off, it doesn't happen.
:> The Adaptec low-level driver has a no-op for the abort function. This
:>means that if a command times out, that the kernel essentially continues to
:>wait for it to complete and no attempt is made to kill the currently running
:>command. If you do not get messages about I/O errors, then this means that the
:>command completed normally and you have nothing to worry about.
:> It would concern me a little to get these messages, however, because
:>this indicates that once in a while the commands take much longer to complete
:>that would normally be expected, and this means that you may have data errors
:>somewhere on the disk (It will take the disk longer to read some particular
:>sector(s) because it needs to retry the operation or use ECC to clean up the
:>bad version of the sector).
:>-Eric
:>--
:>"When Grigor Samsa woke up one morning from unsettling dreams, he
:>found himself changed in his bed into a monstrous vermin."
:> -F. Kafka
I was experiencing similar problems with the Ultrastor 14F driver. The system
would produce two SCSI timeout errors, and wait in an infinite loop. The
problem (inferred from the solution) seems to be that the disk looks larger
than it really is. When Linux attempts an access beyond the end of the disk,
these errors would occur. My solution was to reduce the size of the volume,
leaving some dead space at the end of the disk. I have not had an error since
I set up my filesystem in this fashion.
-J.
-- John P. Silva "I drank WHAT?!" Pacific Systems Integration Internet: jsilva@netcom.com (510)222-9255 GE Mail: J.SILVA1