SOLVED: Which I/O Scheduler is in Use?

[Collins Richey]

On 5/26/05, Kurt Wall <kwall at kurtwerks.com> wrote:

> Someone posting to LKML asked exactly the same question,
> which produce what appears to be a definitive answer:
> 
> $ cat /sys/block/<device>/queue/scheduler
> 
> Thus,
> 
> $ for file in `find /sys -name scheduler`
> > do
> > echo -n "$file: "
> > cat $file
> > done
> /sys/block/fd0/queue/scheduler: noop anticipatory [deadline] cfq
> /sys/block/hdd/queue/scheduler: noop anticipatory [deadline] cfq
> /sys/block/hdc/queue/scheduler: noop anticipatory [deadline] cfq
> /sys/block/hdb/queue/scheduler: noop anticipatory [deadline] cfq
> /sys/block/hda/queue/scheduler: noop anticipatory [deadline] cfq
> 
> The bracketed scheduler is the one in use.
> 

FWIW,

Not on my system (CentOS4 = REHL4). The above script finds nothing.
Here's what my system has:

find /sys -name "*sched*"
./block/fd0/queue/iosched
./block/hdc/queue/iosched
./block/hdb/queue/iosched

Each iosched directory has files quatum and queued.

Nowhere is there any indication of the scheduler in use.

-- 
 Collins
       Head teachers of the world unite: you have nothing to lose but 
       the Start button.