Subject: Re: panic while building a raid-1 set one component at a time
To: None <>
From: Jeff Rizzo <>
List: current-users
Date: 10/08/2003 09:32:15
On Mon, Oct 06, 2003 at 11:43:55AM -0600, Greg Oster wrote:
> Jeff Rizzo writes:
> > After noodling on this for a while, it occurs to me that the machine I'm
> > building this RAID set on before deploying it has only 16MB of memory...
> > Is that little enough to cause this particular issue?  
> Yes, likely.  
> > I know that
> > raidframe is somewhat memory intensive... If so, is there anything I can
> > do kernelwise to strip down the rest of the memory needs so I can get this
> > set built?  
> If you're diddling with a new kernel, try bumping up the NKMEMPAGES 
> values (see 'man options').  (With only 16MB, the default amount of 
> "dedicated kernel memory" is fairly small...)

> [snip]

> Ya.. classic case of "out of kernel memory".  Probably doesn't help 
> that the RAID sets are so big... (to do the reconstruction, RAIDframe
> allocates tables and such to keep track of what's been done, and 
> what's remaining...  with 16MB, only a small chunk of that will be 
> available for the kernel, and RAIDframe can be a resource hog...)

Just FYI for the list, no matter what gyrations I tried with NKMEMPAGES,
I could NOT get this rebuild to work on the system in question.  The
"best" I was able to do was to stop the panic from happening, and get
the reconstruction to deadlock waiting for something (I assume memory).

Anyway, the set is now happily rebuilding on a machine with 256M of
memory that I freed up for the purpose.

Thanks to Greg and Manuel for their responses.

Jeff Rizzo