How to check Disk Performance using iostat Commands ?

Using  iostat command we can get CPU, Device and  Network Filesystem report.

# iostat -xm 2   >> using this command you can see read/write statistics in mb's as below for every 2sec.

#iostat -xm 2 6    >> This will gives performance report of 6 intervals of every 2sec's.

So As per the above examples  

            rrqm/s

                     The number of read requests merged per second that were queued to the device.

              wrqm/s

                     The number of write requests merged per second that were queued to the device.

              r/s

                     The number of read requests that were issued to the device per second.

              w/s

                     The number of write requests that were issued to the device per second.

              rMB/s

                     The number of megabytes read from the device per second.

              wMB/s

                     The number of megabytes written to the device per second.

              avgrq-sz

                     The average size (in sectors) of the requests that were issued to the device.

              avgqu-sz

                     The average queue length of the requests that were issued to the device.

              await

                     The average time (in milliseconds) for I/O requests issued to the device to be served. 

              %util 

                     Percentage of CPU time during which I/O requests were issued to the device (bandwidth                        utilization for the device). Device saturation occurs when this

                     value is close to 100%.

From the above example since we have one Deivce(sda) its ok . If we have multiple Devices how can we know which file is related to what ?

Using #lsblk Command we can find that .