ADIC Time Clock 6-00028-01 Rev A Manuel D’Utilisation

Managing the AMASS File System

6-00028-01 Rev A

Fine-tune Block Size

B-5

Correlate with
READ-BLOCK
LIMIT

A SCSI drive writes to tape in a fixed block segment determined
by the

READ-BLOCK LIMIT

of the drive. This means that at the

end of every write, the last block segment may hold less than
one full block of data. Although this may not, at first, impact
performance, it does waste tape resources if the “average” file
size is small and the

-b

blocksize has been configured for larger

file sizes. This concept is illustrated below.

Tip

The configurable -b blocksize should evenly divide into the
MAXIOSZ

value. This concept is illustrated below.

MAXIOSZ

Size of each tape block
divides evenly into MAXIOSZ.

1/4
Tape
Block
Size

Last segment may be less than full of
client’s data.

Subsequent writes start in this contiguous segment.
If many partially filled segments exist, space is
wasted on the tape.