一般使用iostat命令监控I/O性能
1.iostat命令可用参数列表:
OPTIONS
-c Display the CPU utilization report. -d Display the device utilization report. -h Make the NFS report displayed by option -n easier to read by a human. -k Display statistics in kilobytes per second instead of blocks per second. Data displayed are valid only with kernels 2.4 and
later. -m Display statistics in megabytes per second instead of blocks or kilobytes per second. Data displayed are valid only with ker-
nels 2.4 and later. -N Display the registered device mapper names for any device mapper devices. Useful for viewing LVM2 statistics. -n Display the network filesystem (NFS) report. This option works only with kernel 2.6. and later. -p [ { device [,...] | ALL } ]
The -p option displays statistics for block devices and all their partitions that are used by the system. If a device name is
entered on the command line, then statistics for it and all its partitions are displayed. Last, the ALL keyword indicates that
statistics have to be displayed for all the block devices and partitions defined by the system, including those that have
never been used. Note that this option works only with post 2.5 kernels. -t Print the time for each report displayed. The timestamp format may depend on the value of the S_TIME_FORMAT environment vari-
able (see below). -V Print version number then exit. -x Display extended statistics. This option works with post 2.5 kernels since it needs /proc/diskstats file or a mounted sysfs
to get the statistics. This option may also work with older kernels (e.g. 2.4) only if extended statistics are available in
/proc/partitions (the kernel needs to be patched for that). -z Tell iostat to omit output for any devices for which there was no activity during the sample period.
2.iostat 常用参数举例：
iostat -d -x -k 1 10
$ iostat -d -x -k
Linux 2.6.-.el6.x86_64 (vnode1) 2015年02月25日 _x86_64_ ( CPU) Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 7.23 2923.45 111.97 158.24 4305.81 12331.61 123.14 0.42 1.53 1.55 41.99 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 0.00 1313.00 0.00 38884.00 0.00 59.23 13.14 10.14 0.76 100.10 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 19604.00 587.00 361.00 8380.00 55624.00 135.03 80.47 64.34 1.05 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 1.00 11641.00 93.00 1079.00 4436.00 67312.00 122.44 143.71 119.34 0.85 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 12925.00 91.00 1036.00 6612.00 54072.00 107.69 142.63 133.53 0.89 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 15597.00 66.00 1101.00 3284.00 69080.00 124.02 142.49 124.61 0.86 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 4.00 6834.00 326.00 766.00 10532.00 37696.00 88.33 75.73 80.81 0.92 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 7322.00 417.00 331.00 6796.00 22568.00 78.51 65.42 68.01 1.34 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 12862.00 80.00 1464.00 1424.00 63416.00 83.99 121.29 87.37 0.65 100.00 Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm %util
sda 0.00 0.00 857.00 10.00 12512.00 1972.00 33.41 11.65 14.53 1.15 100.00
iostat -d -k 1 10
$ iostat -d -k
Linux 2.6.-.el6.x86_64 (vnode1) 2015年02月25日 _x86_64_ ( CPU) Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 270.40 4306.84 12331.65 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 812.00 35820.00 56.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 1175.00 24940.00 508.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 910.00 10056.00 12224.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 733.00 2672.00 20064.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 836.00 712.00 10456.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 995.00 604.00 13052.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 966.00 104.00 14264.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 811.00 268.00 19728.00 Device: tps kB_read/s kB_wrtn/s kB_read kB_wrtn
sda 1056.00 124.00 16788.00
更多关于iostat命令的说明可参见转载文章：http://www.cnblogs.com/jyzhao/articles/4299419.html