test

/dev/vda:
 Timing cached reads:   9826 MB in  2.00 seconds = 4919.46 MB/sec
 Timing buffered disk reads:   18 MB in  3.13 seconds =   5.75 MB/sec

/dev/vda:
 Timing cached reads:   8360 MB in  2.00 seconds = 4184.95 MB/sec
 Timing buffered disk reads:   22 MB in  3.41 seconds =   6.45 MB/sec

/dev/vda:
 Timing cached reads:   10058 MB in  2.00 seconds = 5036.60 MB/sec
 Timing buffered disk reads:   26 MB in  3.40 seconds =   7.64 MB/sec