[498] in linux-scsi channel archive
Re: Errors & Unit Attention
daemon@ATHENA.MIT.EDU (Leonard N. Zubkoff)
Sat Aug 12 09:03:37 1995
Date: Sat, 12 Aug 1995 02:03:06 -0700
From: "Leonard N. Zubkoff" <lnz@dandelion.com>
To: eric@aib.com
Cc: linux-scsi@vger.rutgers.edu
In-Reply-To: <9508101016.ZM797@aib.com> (eric@aib.com)
From: "Eric Youngdale" <eric@aib.com>
Date: Thu, 10 Aug 1995 10:16:57 -0400
A unit attention is treated as a media change, as this is the way
that these things are normally reported. The reason you are locked out from
the drive is that the kernel is assuming that you do not have the same media
in the drive as was in there when the disk was mounted. If you unmount the
disk and remount it, you should get access again.
I don't think it's quite this simple. As I read the code in sd.c, this only
happens for disk devices that are marked "removable". An ordinary disk falls
through that case and eventually prints an error message. I'm still not clear
on what happens after that error, though. Processes frequently hang with a "D"
status, and all further file system access to the disk fails. Why?
Leonard
