[Trilug-ontopic] Process priority

[David Black]

You may find using a different I/O scheduler will help.  Assuming a 2.6
kernel, here's some background: http://www.linuxjournal.com/article/6931

In recent 2.6 kernels the default I/O scheduler is cfq, and is
selectable on a per-device basis.  Here's how to change it to (for
instance) deadline for /dev/hda:

# cd /sys/block/hda/queue
# cat scheduler
noop anticipatory deadline [cfq]
# echo deadline > scheduler
# cat scheduler
noop anticipatory [deadline] cfq

The 'best' I/O scheduler depends on the kind of load the machine is
seeing.  Since there are currently only four to choose from, why not try
your test with each?

Dave

Jason Watts wrote:
> so... i discovered (it was quite obvious actually) that to run an rsync
> and an un-tar command at the same time on the same set of drives that it
> really causes the system to lag.
>  
> My question is for the next time I need to do something like that.  how
> would I set the priority of the un-tar to a lower priority... that way
> it is only using what resources are left over that aren't being used? 
> if that's really possible  (my bottleneck was actually the spindle
> speeds of the drives)
>  
> thanks,
> Jason
> 
> 
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