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02. [5p] Iostat
Good to know
#iostat [ -x for extended statistics, -d to display device stastistics only, -m for displaying r/w in MB/s ] iostat -xdm #iostat with -p for specific device statistics iostat -xdm -p sda
Monitoring the behaviour
- Run iostat -x 1 5.
- Considering the last two outputs provided by the previous command, calculate the efficiency of IOPS for each of them. Does the amount of data written per I/O increase or decrease?
How to's
- Divide the kilobytes read (rkB/s) and written (wkB/s) per second by the reads per second (r/s) and the writes per second (w/s).
- If you happen to have quite a few loop devices in your iostat output, find out what they are exactly:
$ df -kh /dev/loop*
