Shulou(Shulou.com)06/03 Report--

The above columns have the following meanings:

Rrqm/s: the number of read requests to the device per second are merged, and the file system merges requests for reading the same block (block)

Wrqm/s: the number of write requests to the device that were merged per second

Ripple s: the number of reads completed per second

Whand s: the number of writes completed per second

RkB/s: data read per second (in kB)

WkB/s: the amount of data written per second (in kB)

Avgrq-sz: average amount of data per IO operation (number of sectors)

Avgqu-sz: average queue length of IO requests waiting to be processed

Await: average wait time per IO request (including waiting time and processing time, in milliseconds)

Svctm: average processing time per IO request (in milliseconds)

% util: the ratio of time spent on IO operations in the cycle, that is, the rate of time that the IO queue is not empty

Command: iostat-d-x-m (display message is MB megabytes) 10 (seconds)

Device: rrqm/s wrqm/s rUnip s rMB/s wMB/s avgrq-sz avgqu-sz await svctm% utilsda 0.00 2.10 0.00 42.50 0.00 9.14 440.56 1.60 37.65 0.39 1.66dm-0 0.00 0.00 44. 60 0.00 9.14 419.82 1.63 36.46 0.36 1.62dm-1 0.00 0.00 0.00

For the sample output above, we can get the following information:

Write about 30m of data per second to the disk (wkB/s value)

There are 91 IO operations (r/s+w/s) per second, with write operations as the main body

The average waiting time for each IO request is 120.57 milliseconds, and the processing time is 6.33ms.

An average of 11.79 requests reside in the queue of IO requests waiting to be processed

There is also a relationship between the above values, and we can calculate other values from some values, such as:

Util = (r/s+w/s) * (svctm/1000)

For the above example, util = (1 to 90) * (6.33 to 1000) = 0.57603

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