ADIC 6-00028-01 Rev A manual 427

Managing the AMASS File System

Tip

The configurable -b blocksize should evenly divide into the

MAXIOSZ value. This concept is illustrated below.

1/4	1/4	1/4	1/4
Tape	Tape	Tape	Tape	Size of each tape block
Block	Block	Block	Block	divides evenly into MAXIOSZ.
Size	Size	Size	Size

MAXIOSZMAXIOSZ

Correlate with	A SCSI drive writes to tape in a fixed block segment determined
READ-BLOCK	by the READ-BLOCK LIMIT of the drive. This means that at the
LIMIT	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 -bblocksize has been configured for larger
	file sizes. This concept is illustrated below.

Last segment may be less than full of	Subsequent writes start in this contiguous segment.
client’s data.	If many partially filled segments exist, space is
	wasted on the tape.

6-00028-01 Rev A Fine-tune Block Size B-5