Re: [uml-user] Making the most of ubds?

[Jeff D. <jd...@ad...>]

On Thu, Dec 08, 2005 at 03:06:28PM +0100, Joel Palmius wrote:
> Are there any general recommendations for making throughput on UBDs more 
> efficient? Such as kernel settings, recommended filesystems..?
> 
> Doing an "emerge sync" inside an uml raises iowait to 100% and load to 7, 
> making the machine more or less inaccessible. Just wondering if it's me 
> having bad settings.

I strongly suspect a bad interaction with the host I/O scheduler, although
I can't prove anything.  The UML is just passing read/write requests to the
host and expecting them to be handled somewhat efficiently.

Using AIO helps (~25% on a kernel build), but I still see the same basic
symptoms (nothing running, everything in iowait).

				Jeff