Subject: Re: Possible serious bug in NetBSD-1.6.1_RC2
To: Brian Buhrow <>
From: Greg Oster <>
List: current-users
Date: 03/11/2003 22:57:08
Brian Buhrow writes:
> 2.  I'm notcertain, but my guess is that the reason raid5 works under 1.5R
> and not 1.6 is not so much due to the changes in raidframe itself, but,
> rather, changes in the way kernel memory is managed by uvm.  They may be
> only tuning changes, but something definitely changed.

So whatever the problem is, I can reliably lockup my test box in seconds
when swapping to a RAID 5 set... Using the same test I couldn't kill my 
test box when swapping to a RAID 1 set.  

Workaround to the problem: Swap to a RAID 1 set instead of a RAID 5 set.  
While reads might not be as fast, writes will be (likely) 4x faster, which 
should improve your swapping/paging performance too!

Figuring out what the problem is will require some additional testing,
and that will have to wait until at least tomorrow... :-}

Thanks to everyone who helped narrow down the problem...


Greg Oster