I have made a simple tool to measure idle and busy time for
block devices.

I have been wanting something like this for a while, because
the absolute throughput/seek numbers don't always help you
determine whether or not a workload is becoming IO bound.

It requires a small kernel patch, and I've also attached my
lame userspace program for it. It is kind of like vmstat.

Oh, and before I go further, does anyone know of any program
or statistic that allows the same functionality? Any comments?

** sample output **
npiggin@didi:~/blk$ ./blkstat hda
bdev      bi %    bo %    io %    id %
hda        0.0     0.0     0.0   100.0
hda        0.0     0.0     0.0   100.0
hda        1.2     0.0     1.2    98.8
hda       48.1     0.0    48.1    51.9
hda       53.6     0.0    53.6    46.4
hda       47.1     0.0    47.1    52.9


Nick

-- 
SUSE Labs, Novell Inc.