lkml.org 
[lkml]   [1999]   [Nov]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRe: LOTS OF BAD STUFF in raid0: raid0145-19990824-2.2.11 is unstable
Date
I had problems with the "beyond end of device" message quite regularly until
I switched the device from non-RAID to RAID and replaced the CPU.

I was able to reproduce this with an application that was extremely heavy
I/O on a single SCSI disk (this was linear file access on about 20G of
data). This was on a dual PIII-450. Once I switched to a 3x50G RAID device
the problems went away ( I even had one of the "beyond" messages while I was
copying). However, I then started having lockups instead of "beyond" -- and
I finally traced it down to one of the CPUs (turns out one of them was
overheating). When I replaced the PIII-450's with two new PIII-500's the
system has been rock solid since (I'm now running 2.2.13 with the 2.2.11
RAID patch compiled on gcc 2.95-2)

I have another box that was Non-SMP (Kernel is SMP though) PII/233 IDE that
I saw the "beyond end of device" message once. So, I think that eliminates
SCSI, RAID, and SMP as likely candidates.

So, I think there really is a bug (or maybe just a behaviour) lurking in the
i/o buffers that just gets exacerbated by other problems, heavy I/O, cache
problems (like overheated CPU), cables, etc.

Maybe we could put a "marker" in the buffer_head at certain points to see if
it gets walked on?
----- Original Message -----
From: P.A.M. van Dam <nucleus@ramoth.xs4all.nl>
To: Florian Lohoff <flo@rfc822.org>
Cc: David Mansfield <david@cobite.com>; <linux-raid@vger.rutgers.edu>;
<linux-kernel@vger.rutgers.edu>; Ingo Molnar <mingo@chiara.csoma.elte.hu>;
Alan Cox <alan@lxorguk.ukuu.org.uk>
Sent: Saturday, November 06, 1999 2:40 PM
Subject: Re: LOTS OF BAD STUFF in raid0: raid0145-19990824-2.2.11 is
unstable


On Sat, Nov 06, 1999 at 03:44:47PM +0100, Florian Lohoff wrote:
>
> Easy setup
>
> raid0 of raid5s ...
>
> read:
>
> /dev/md0 raid0 /dev/md1 /dev/md2
> /dev/md1 raid5 scsi disks (tried with 6 and 3)
> /dev/md2 raid5 scsi disks (tried with 6 and 3)
>
> As soon as you initiate a "mke2fs /dev/md0" the machine
> hangs with "Got md request, not good" (md.c -> do_md_request())

Same here, but then with Mauelschagens LVM. An mkfs -t ext2 for the
first time (after bootup) on a striped LV will trigger the "Got LVM
request, not good" message (and accompanied by some "trying to ...
beyond end of device" messages). The second attempt will not generate
these messages.

I'm sorry, but I still have the strong belief that this isn't hardware
nor RAID (only) related. There must be some bug lurking, we have to
stamp out before we can take 2.4 seriously.


>
> I reproduced this with different hardware (machines, harddrives, scsi
controllers etc - Even on sparc ...)

Ok. Does SMP be the common denominator in your test? Almost all reports
are with SMP machines.

>
> >From the manpage this is a feature which should work.

Best regards,

Pascal

>
> Flo
> --
> Florian Lohoff flo@rfc822.org +49-5241-470566
> ... The failure can be random; however, when it does occur, it is
> catastrophic and is repeatable ... Cisco Field Notice
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu
> Please read the FAQ at http://www.tux.org/lkml/


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:54    [W:0.074 / U:1.028 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site