Code:
diskinfo -c -t /dev/ad0
/dev/ad0
512 # sectorsize
80026361856 # mediasize in bytes (75G)
156301488 # mediasize in sectors
155061 # Cylinders according to firmware.
16 # Heads according to firmware.
63 # Sectors according to firmware.
WD-WCAJD1048022 # Disk ident.
I/O command overhead:
time to read 10MB block 0.198769 sec = 0.010 msec/sector
time to read 20480 sectors 1.698406 sec = 0.083 msec/sector
calculated command overhead = 0.073 msec/sector
Seek times:
Full stroke: 250 iter in 5.653904 sec = 22.616 msec
Half stroke: 250 iter in 4.002821 sec = 16.011 msec
Quarter stroke: 500 iter in 6.254353 sec = 12.509 msec
Short forward: 400 iter in 2.406205 sec = 6.016 msec
Short backward: 400 iter in 3.432481 sec = 8.581 msec
Seq outer: 2048 iter in 0.176710 sec = 0.086 msec
Seq inner: 2048 iter in 0.344202 sec = 0.168 msec
Transfer rates:
outside: 102400 kbytes in 1.843513 sec = 55546 kbytes/sec
middle: 102400 kbytes in 2.023078 sec = 50616 kbytes/sec
inside: 102400 kbytes in 3.261300 sec = 31399 kbytes/sec
Disk is old a little more than six years.