Subject: Re: PR kern/20191, plea for fix in 1.6.2!
To: Greg Oster <oster@cs.usask.ca>
From: Greg A. Woods <woods@weird.com>
List: tech-kern
Date: 11/16/2003 13:22:51
[ On Sunday, November 16, 2003 at 10:12:00 (-0600), Greg Oster wrote: ]
> Subject: Re: PR kern/20191, plea for fix in 1.6.2! 
>
> Nicolai Stevens writes:
> > I noticed that the release process for 1.6.2 has begun
> > and is in the release candidate stage.  However, it
> > doesn't look like there has been any fix committed to
> > the branch for the RAID5/low kernel memory lockup
> > described in PR 20191.  I seem to be running across
> > this crash/hang quite often on one particular
> > production server. 
> 
> Assuming you need the RAID more than you need softdeps, 
> a workaround is to just turn off softdeps.

Does anyone know enough about this problem yet to know if the
relationship causing the lockup is directly between the RAIDframe device
and having soft-dependencies enabled for a filesystem on that same
device?

I.e. is it known to be less likely for a lockup to occur if soft-
dependencies are enabled only on other filesystems not related to the
RAIDframe device?

Anecdotally from my own experiences I would guess this lockup is indeed
caused by a direct competition between RAIDframe and the filesystem
using RAIDframe.

It also seems to me that RAID-5 sets are far more likely to encounter
problems than RAID-1 or RAID-0 sets.

If any of these conditions can be proven more scientifically then I
think it would be a darn good idea to mention them precisely in the
1.6.2 release notes.....

-- 
						Greg A. Woods

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