Re: disk diagnostics

["Pieter Dumon" <pieter.dumon@xxxxxxxxx>]

You're right: softdep did the trick. Turned it on on the /usr/obj
filesystem, and the rm of the whole world_i386 of 1.7 preview took
about 10 seconds....

Thanks! I didn't expect soft updates to make such a huge difference.

Pieter


On 7/27/06, Joerg Sonnenberger <joerg@xxxxxxxxxxxxxxxxx> wrote:
> On Thu, Jul 27, 2006 at 05:46:49PM +0800, Bill Hacker wrote:
> > >0.070u 0.476s 20:11.87 0.0%     313+264k 7+54102io 0pf+0w
> > >
> >
> > Am I wrong in interpreting that said act took 7 1/100's of a second of CPU
> > time for itself, needed just under half a second of system overhead, but
> > needed 20+ minutes end-to-end to complete by the wall-clock?
> >
> > 'To be determined' if it was awaiting I/O, or if something else was denying
> > it a place to sit down and eat its hamburger.
>
> That's exactly what I expected. It needs almost no processing in
> userland, a little bit more in the kernel to push the IO through the
> various layer and most time waiting for the ATA controller. When you
> repeat the same process with softdep, it should be a lot faster, since
> it can write out many requests ordered. It would be even faster with a
> proper disk scheduler, but that's (still) a dream.
>
> Joerg