Re: puzzling scsi return code 20000

[Andrew Vasquez <praka@users.sourceforge.net>]

On Mon, 05 Jul 2004, Yann Dupont wrote:

> hello. I have some problems with a SAN here. Don't know if the problems 
> lies in scsi code/driver or other thing...
> 
> The setup is :
> a QLA2300 (Fibre channel) with 6.0.64 driver from qlogic site,
>

I'm not familiar with that version number (are you sure it's 6.0.64,
perhaps 6.06.64?).  I believe the latest driver submitted to DVT has
been posted to the website (7.00.03).

> 2.4.26 kernel, device mapper 1.0.17 applied,
> and xfs or reiserfs on top of lvm volumes (using evms)
> 
> This setup seemed fine since some months now, with giga of data moved 
> every day, but I noticed this on the log:
> 
> Jun 22 16:45:15 talisker kernel: SCSI disk error : host 3 channel 0 id 2 
> lun 1 return code = 20000
> Jun 22 16:45:15 talisker kernel:  I/O error: dev 08:10, sector 145423312
> 
> I have two of these errors in the last month. What's the meaning of this 
> return code ? I made
> badblock on the /dev/evms volume, and all is OK.
>

20000 == DID_BUS_BUSY -- one possibility, the QLogic driver returned a
command with the status, mid-layer ran out of retries, subsequently
returning the status to the upper-layer driver.  But that doesn't
help in finding out what went wrong.

> I also performed a disk scan on the raid array, (an IFT 7250F) and there 
> are no errors.
> 
> The machine can be quite heavily loaded. May I suspect the qla driver ? 
> May I suspect the underlying LVM. The LVM has been resized by the 
> past... Can an error happens here too ?
> I'm very puzzled...
> 
> This is just a summary . I can furnish more information if needed.
> 

I'd suggest you try a more recent driver (noted above), if the I/O
errors persist, then report the problem to tech-support at:

	http://connection.qlogic.com/support/report/index.asp?id=csg

with a complete description.

Regards,
Andrew Vasquez
QLogic Corporation