Subject: Re: SCSI bus parity error
To: Toru Nishimura <nisimura@itc.aist-nara.ac.jp>
From: Gregory McGarry <g.mcgarry@ieee.org>
List: port-pmax
Date: 06/26/2000 08:18:59
Toru Nishimura wrote:

> During stress test of tape drive access, my MAXINE paniced twice complaining
> "SCSI bus parity error".  Is it a hardware problem, or possible software
> driver implemention flaw?  The tape drive is TKZ15, rebadged EXB-85xx,
> and is running 2GB+ worth of data repeatedly.
> 
> st0(xasc0:5:0): xasc0: timed out [ecb 0xc0011138 (flags 0x103, dleft 0, stat 0)], <state 1, nexus 0x0, phase(l 10, c 100, p 3), resid 0, msg(q 0,o 0) >
> xasc0: SCSI bus parity error
> panic: xasc0: invalid state: 6
> Begin traceback...
> SP 0x0: not in kernel
> _DYNAMIC_LINK+0 (0,0,0,0) ra 0 sz 0
> User-level: pid 63
> End traceback...
> syncing disks... 1 1 1 1 1 1 1 1 st0(xasc0:5:0): xasc0: timed out [ecb 0xc00110d0 (flags 0x7, dleft 3, stat 0)], <state 6, nexus 0xc00110d0, phase(l 6, c 6, p 3), resid 3, msg(q 4,o 0) >
> 1 1 1 1 1 st0(xasc0:5:0): xasc0: timed out [ecb 0xc00110d0 (flags 0x47, dleft 3, stat 0)], <state 6, nexus 0xc00110d0, phase(l 6, c 6, p 3), resid 3, msg(q 4,o 0) > AGAIN
> sd0(xasc0:2:0): max sync rate 5.00MB/s
> done

I wasn't seeing any problems.  My MAXINE has two internal RZ25s and
one external RZ25.  Usually they all spinup.  However, over the weekend
I didn't power-up the external drive.  The two internal drives exhibited
similar behaviour as you have observed.  I powered-up the external drive
and they went away.  I didn't get a panic though.  This was with
1.4ZB.  I will try an reproduce it.

Does anyone have a brief specification of SCSI which isn't 600 pages long?

	-- Gregory McGarry <g.mcgarry@ieee.org>