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root@test:~ # diskinfo -c /dev/vtbd0
/dev/vtbd0
        512             # sectorsize
        53687091200     # mediasize in bytes (50G)
        104857600       # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        104025          # Cylinders according to firmware.
        16              # Heads according to firmware.
        63              # Sectors according to firmware.
                        # Disk ident.

I/O command overhead:
        time to read 10MB block      0.085699 sec       =    0.004 msec/sector
        time to read 20480 sectors  12.162316 sec       =    0.594 msec/sector
        calculated command overhead                     =    0.590 msec/sector




root@test:~ # diskinfo -t /dev/vtbd0
/dev/vtbd0
        512             # sectorsize
        53687091200     # mediasize in bytes (50G)
        104857600       # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        104025          # Cylinders according to firmware.
        16              # Heads according to firmware.
        63              # Sectors according to firmware.
                        # Disk ident.

Seek times:
        Full stroke:      250 iter in   0.090048 sec =    0.360 msec
        Half stroke:      250 iter in   0.103293 sec =    0.413 msec
        Quarter stroke:   500 iter in   0.970505 sec =    1.941 msec
        Short forward:    400 iter in   0.549123 sec =    1.373 msec
        Short backward:   400 iter in   1.195440 sec =    2.989 msec
        Seq outer:       2048 iter in   0.879379 sec =    0.429 msec
        Seq inner:       2048 iter in   0.876517 sec =    0.428 msec
Transfer rates:
        outside:       102400 kbytes in   0.794245 sec =   128927 kbytes/sec
        middle:        102400 kbytes in   0.502954 sec =   203597 kbytes/sec
        inside:        102400 kbytes in   0.262135 sec =   390638 kbytes/sec

root@test:~ # diskinfo -c /dev/vtbd0
/dev/vtbd0
        512             # sectorsize
        53687091200     # mediasize in bytes (50G)
        104857600       # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        104025          # Cylinders according to firmware.
        16              # Heads according to firmware.
        63              # Sectors according to firmware.
                        # Disk ident.

I/O command overhead:
        time to read 10MB block      0.059608 sec       =    0.003 msec/sector
        time to read 20480 sectors   5.189635 sec       =    0.253 msec/sector
        calculated command overhead                     =    0.250 msec/sector

root@test:~ # diskinfo -t /dev/vtbd0
/dev/vtbd0
        512             # sectorsize
        53687091200     # mediasize in bytes (50G)
        104857600       # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        104025          # Cylinders according to firmware.
        16              # Heads according to firmware.
        63              # Sectors according to firmware.
                        # Disk ident.

Seek times:
        Full stroke:      250 iter in   0.117120 sec =    0.468 msec
        Half stroke:      250 iter in   0.038454 sec =    0.154 msec
        Quarter stroke:   500 iter in   0.270352 sec =    0.541 msec
        Short forward:    400 iter in   0.411616 sec =    1.029 msec
        Short backward:   400 iter in   0.737363 sec =    1.843 msec
        Seq outer:       2048 iter in   0.479056 sec =    0.234 msec
        Seq inner:       2048 iter in   0.460345 sec =    0.225 msec
Transfer rates:
        outside:       102400 kbytes in   0.252984 sec =   404769 kbytes/sec
        middle:        102400 kbytes in   0.295906 sec =   346056 kbytes/sec
        inside:        102400 kbytes in   0.194296 sec =   527031 kbytes/sec

-o preallocation=metadata