On Wed, 2011-01-05 at 13:37 +0100, Stephan Wiesand wrote:
> Hi,
> 
> On Jan 5, 2011, at 13:30, g1vrg wrote:
> 
> > Hi, I have noticed that in default SL5.5 disk operations tend to hugely
> > tie up my pc. For example when writing large files (of the order of 10
> > GB) I may have to wait 30 seconds before I can get a response from
> > another application on the desktop. Is there another i/o scheduler other
> > than the default that I can specify presumably as a kernel command in
> > the grub boot loader config file? I recently swapped over from debian
> > lenny and the i/o scheduler there
> 
> which one was it?

Sorry I don't know. 

> 
> You can change I/O schedulers per block device on the fly:
> 
> # cat /sys/block/sda/queue/scheduler
> noop anticipatory deadline [cfq] 
> # echo noop >> /sys/block/sda/queue/scheduler
> # cat /sys/block/sda/queue/scheduler
> [noop] anticipatory deadline cfq 
> 
> I guess you get the idea. Let us know which one works best for you (and what hardware you have).
> 

Ok thanks. I tried elevator=noop, elevator=as and elevator=deadline

They were each pretty much the same. If I do a large file copy or dd
operation I get freezes on the desktop and xmms freezes and stops
playing music for example.

The hardware is a seagate 250GB sata drive with lvm on a msi mobo with
amd64 cpu (3700+ @2.2 GHz) with 32bit SL5.5.

maybe I need to pass some CFQ params? Or it could be something else
entirely. It's just these file operations that cause the trouble for me
(and the wife! lol - she was on debian before and i switched her).

Anyway, if anyone else has noticed this and has a fix they know of I'd
appreciate a reply. I don't want to try lots of experiments or tests,
I'll be moving on to SL 6 when it's out in March time.

Thanks
Richard G