Subject: Re: RAIDFrame and RAID-5
To: Thomas Hertz <thomas@hz.se>
From: Greg Oster <oster@cs.usask.ca>
List: current-users
Date: 09/08/2003 07:51:41
"Thomas Hertz" writes:
> 
> I've been running a raid-5 set with three disks more or less
> successfully for several months now. It took a little tweaking to get it
> reasonably stable (with alot of help from the tweaks by Paul Ripke in
> kern/20191). Last week I got myself another two disks, and went through
> the process of backup up all my data to create a brand new shining
> five-disk raid-5 array.
>  
> Apparently this was a mistake. It seems as if the bigger the diskspace,
> the more unstable is RAIDFrame.  So, does anyone have any piece of advice
> to make this usable? 

What sorts of problems are you seeing?  Panics?  Freezes?  Can we 
please get 'dmesg' output, 'raidctl -s' output, raid config files, etc, etc?

> Should I increase uvmexp.reserve_kernel even more?
> What are the consequences of doing so? (it's set to 48 now, was thinking
> of increasing it to 128).
>  
> The lack of working software raid-5 might even force me to migrate to
> Linux (yuck..).

Here's a 5-disk RAID 5 set that's been working just peachy for a 
couple of years now:

/dev/raid2e    279877580 81534600 184349100    30%    /u1

Here's a 3-disk RAID 5 set that's been happy for a few years too:

/dev/raid3e  89270792 51783696  33023556    61%    /u3

Both of these are on 1.6 boxes... (Hmm.. I wonder if something has 
changed since 1.6 that is causing problems in low-kernel-memory 
conditions...)

Later...

Greg Oster