Identifying disk I/O bottlenecks

In this recipe, we are going to use the iostat command to identify disk-related bottlenecks.

How to do it...

There are various options, that is, switches, available with the iostat command. The following are the most important switches used with iostat:

1. -d: This switch reports the number of kilobytes transferred per second for specific disks, the number of transfers per second, and the average service time in milliseconds. The following is the usage of the iostat -d command:

           bash-3.2$iostat -d 5  5 
    
           sd0            sd2         sd3          sd4 
           Kps tps serv  Kps tps serv Kps tps serv Kps tps serv 
           1   0    53   57  5  145    19 1   89    0   0  14 
           140 14   16   0   0   0    785 31  21    0   0  0 
           8   1    15   0   0   0    814 36  18    0   0  0 
           11  1    82   0   0   26   818 36  19    0   0  0 
           0   0    0    1   0   22   856 37  20    0   0  0 
   ...