On Fri, Feb 08, 2008 at 07:03:19AM -0800, Paul Goyette wrote:
> I've actually been seeing this for a while - at least since 4.99.39 ...
> 
> Occassionally it seems that disk I/O activity just stalls.  currently I've 
> got a dump(8) running on the filesystem that contains /usr/src and /usr/obj 
> .  The dump has been running for more than 5 hours now, and it making 
> extremely slow progress.  Sometimes the dump takes 9 or 10 hours before it 
> finishes!  The hard drive activity light blinks about once a second - it 
> should be on solid, since the machine is doing nothing else.
...
> Has anyone else seen similar behavior?  Any clues on how to track down the 
> cause of this slowness?

Just a thought: is this a DEBUG/DIAGNOSTIC/LOCKDEBUG kernel? With
one such kernel, making a release took about 13 hours, removing
those options, and changing nothing else, knocked the time down to
under 2 hours.

Cheers,

Patrick