Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 2 Nov 1998 00:10:58 +0100
From:      Bernd Walter <ticso@cicely.de>
To:        "Justin T. Gibbs" <gibbs@narnia.plutotech.com>
Cc:        current@FreeBSD.ORG
Subject:   Re: scsi disk (cam?) problems
Message-ID:  <19981102001058.41129@cicely.de>
In-Reply-To: <199811011924.MAA08917@narnia.plutotech.com>; from Justin T. Gibbs on Sun, Nov 01, 1998 at 12:24:09PM -0700
References:  <199811010132.UAA04810@bb01f39.unx.sas.com> <199811011924.MAA08917@narnia.plutotech.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Sun, Nov 01, 1998 at 12:24:09PM -0700, Justin T. Gibbs wrote:
> In article <19981101195246.10586@cicely.de> you wrote:
> > Very interesting.
> > I've saw the same message yesterday:
> > Oct 31 20:10:18 cicely5 /kernel: (da23:ahc4:0:1:0): Invalidating pack
> 
> What kinds of power supplies are all of you using?  The reason the
It's a new Power-Supply so maybe it's broken.
The supply has only this SCSI-Chain with 4-CDOMs 1 Streamer 1 HDD
and this MO Drive.
Only the MO Drive was used from this Supply at the time of the error.
Don't shure about the cabeling, because it's only up for 2 days.

I'll check it.
> pack is being invalidated is that the drive in question is not
> responding within a selection timeout period (250ms).  This is
That's long - but I don't know how the drive handles media-errors.
At least my Win-NT Host on which the drive was connected before
has done serveral bus-resets in case of an media-problem.
They were reproduceable on the same sectors.
So maybe the firmware s broken.

> usually because of a device no being there, but I suspect in this
> case the cause is a parallel I/O load that pushes your drives
> to their maximum power rating, saturating your power supply leaving
> one or more devices starving for power.  Any I/O attempted while
> the drive is going through a power-on reset is likely to fail with
> a selection timeout.
If it was a complete power-on reset the old SCSI-code would have given
me some information about during the next access - I asume CAM is doing
the same.
In case of a bus-problem I'm used to see things like bus-resets.
I don't realy like them - especialy with Streamers on the same bus - but
I'm shure sometimes they are sensefull.
What I don't understand is why the system can't recover from that failure.
as mentioned earlier the drive is still accessable via camcontrol but not
via the mounted fsdriver.

> 
> I will change the error handler for the selection timeout case to
> return EIO instead of ENXIO, but this is just a temporary work around
By the way I'm not so deep into this - what are the differences?

> until we can provide a better pack invalidation scheme in the system.
> 
> --
> Justin

-- 
Mfg B.Walter


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-current" in the body of the message



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?19981102001058.41129>