io

root@sql:~# hdparm -tT /dev/xvda1

/dev/xvda1:
 Timing cached reads:   394592 MB in  2.00 seconds = 197790.28 MB/sec
 Timing buffered disk reads: 128 MB in  0.00 seconds = 32016.01 MB/sec

root@web:~# hdparm -tT /dev/xvda1

/dev/xvda1:
 Timing cached reads:   11798 MB in  1.99 seconds = 5922.69 MB/sec
 Timing buffered disk reads: 1024 MB in  2.09 seconds = 489.48 MB/sec

root@hypervisor:~# hdparm -tT /dev/sda1

/dev/sda1:
 Timing cached reads:   11270 MB in  1.99 seconds = 5665.99 MB/sec
 Timing buffered disk reads: 196 MB in  1.72 seconds = 114.18 MB/sec