Output of the Iostat

The first line shows the average value since the subsystem was started, and the next report shows the average of the increments, one row per Device

device:rrqm/s wrqm/s r/s w/s rsec/s wsec/s avgrq-sz avgqu-sz await SVCTM%util

SDA 0.00 23.75 0.00 5.79 0.00 236.33 40.83 0.02 3.10 0.76 0.44
Dm-0 0.00 0.00 0.00 29.54 0.00 236.33 8.00 0.11 3.56 0.15 0.44
Dm-1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

rrqm/s wrqm/s

Merged read and write requests per second, "merged" means that the operating system takes multiple logical requests from the queue to merge into a single request to the actual disk

r/s W/S Read and write requests sent to the device per second

RSEC/S wsec/s number of reads and writes per second, some systems are also output to rkb/s and wkb/s, which means the number of kilobytes per second read and write

AVGRQ-SZ number of sectors requested

Avgqu-sz number of requests waiting in the device queue-----------didn't understand.

The number of milliseconds spent waiting on a disk

SVCTM the number of milliseconds that the service request took, not including the queue time-------execution time?

%util percentage of time spent at least one active request ——-----------didn't understand.