Re: Linux 2.6.31 - very swap-happy with plenty of free RAM

From: Bill Davidsen
Date: Thu Nov 26 2009 - 20:56:40 EST


Dan Merillat wrote:
On Wed, Nov 18, 2009 at 4:45 PM, Tomasz Chmielewski <mangoo@xxxxxxxx> wrote:

I have a pretty powerful desktop machine with 8 GB RAM, fast disks with
RAID-1 etc.

Every 10 minutes or so, machine is really unresponsive, load jumps to 10 or
20. Mouse pointer jumps, it's impossible to change between windows etc.

This is the type of hefty workstation many of the core developers
have, running similar workloads, so I'm somewhat surprised that the
default VM settings have this kind of issue.

Do a "swapoff -a", and everything is snappy and responsive as it should,
there are no more lags.

Yes, that's my exact finding.

Is this weird IO storm happening for anyone else with plenty of memory
(for their taskload?)

My load is virtually the same a Tomasz describes, virtual machines (including this desktop), little backup servers on CentOS-5.3, production Fedora-9 and 10, testing FC11 and 12. I see none of this problem, with the Fedora kernel or my own build of 2.6.31 whatever was stable two weeks ago.

What is not the same is that all are started from CLI and scripts, because much of my VM stuff predates libvirt. So nothing between qemu-kvm and my fingers or boot scripts.

I have no idea if this is useful or significant, just sharing it "in case."

--
Bill Davidsen <davidsen@xxxxxxx>
"We have more to fear from the bungling of the incompetent than from
the machinations of the wicked." - from Slashdot

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