Apr 2017
IOStat gives information (disk performance) about the disk activity in a Linux environment. Useful information such as disk reads/writes and activity (% busy).
IOStat is a handy tool to ensure that you are not overworking the disks, this is especially useful on products like VSPP where disk usage can be exceeded before any CPU performance issues occur.
To use, from the command line simply enter iostat
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iostat
avg-cpu: %user %nice %system %iowait %steal %idle
33.60 0.00 0.50 0.02 0.00 65.87
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
sda 7.36 0.19 1112.01 967702 5556997874
sdb 0.00 0.00 0.00 1496 0
dm-0 139.00 0.19 1112.01 956514 5556997832
dm-1 0.00 0.00 0.00 2400 0
dm-2 0.00 0.00 0.00 2178 24
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We can use another command line to get periodica.iostat updates iostat 10 -x
<sxh [text][; options for SyntaxHighlighter]>
iostat 10 -x
avg-cpu: %user %nice %system %iowait %steal %idle
33.61 0.00 0.50 0.02 0.00 65.86
Device: rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await r_await w_await svctm %util
sda 0.00 132.62 0.00 7.36 0.19 1112.07 151.05 0.05 6.75 2.34 6.75 3.01 2.22
sdb 0.00 0.00 0.00 0.00 0.00 0.00 8.00 0.00 0.18 0.18 0.00 0.18 0.00
dm-0 0.00 0.00 0.00 139.01 0.19 1112.07 8.00 0.71 5.13 3.92 5.13 0.16 2.22
dm-1 0.00 0.00 0.00 0.00 0.00 0.00 8.00 0.00 1.42 1.42 0.00 0.60 0.00
dm-2 0.00 0.00 0.00 0.00 0.00 0.00 7.92 0.00 0.59 0.51 5.00 0.44 0.00
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