How can I monitor disk io? sar from sysstat | iotop | dstat
My personal favorite is the
sar
command from sysstat
. By default, it gives output like this:09:25:01 AM CPU %user %nice %system %iowait %steal %idle
09:35:01 AM all 0.11 0.00 0.01 0.00 0.00 99.88
09:45:01 AM all 0.12 0.00 0.01 0.00 0.00 99.86
09:55:01 AM all 0.09 0.00 0.01 0.00 0.00 99.90
10:05:01 AM all 0.10 0.00 0.01 0.02 0.01 99.86
Average: all 0.19 0.00 0.02 0.00 0.01 99.78
The
%iowait
is the time spent waiting on I/O. Using the Debian package, you must enable the stat collector via the /etc/default/sysstat
config file after package installation.
To see current utilization broken out by device, you can use the
iostat
command, also from the sysstat package:$ iostat -x 1
Linux 3.5.2-x86_64-linode26 (linode) 11/08/2012 _x86_64_ (4 CPU)
avg-cpu: %user %nice %system %iowait %steal %idle
0.84 0.00 0.08 1.22 0.07 97.80
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await svctm %util
xvda 0.09 1.02 2.58 0.49 112.79 12.11 40.74 0.15 48.56 3.88 1.19
xvdb 1.39 0.43 4.03 1.82 43.33 18.43 10.56 0.66 112.73
Comments
Post a Comment