Yamaha CBX-D5 - Manual (Page 25)

Hard disk fragmentation 19 Hard disk fragmentation 19 Hard disk fragmentation 19
Hard disk fragmentation
Hard disks record data into pre-formatted concentric tracks on a number of magnetic disks
that are mounted around a common spindle. Tracks are further divided into sectors, and
each sector can store 512bytes of data. On a newly formatted disk, files are recorded into
a continuous series of sectors as shown below.
As files are deleted and new files saved, files may be split (fragmented) over different areas
of the disk, losing the continuity of sectors. In this case, reading one file may cause the disk
drive to read sectors from many different parts of the disk, thus slowing down the overall
data read rate and making the disk drive work harder.
Disk defragmentation is quite important for hard disk audio recording, as it is better to
record data into a continuous series of empty hard disk sectors. If recording starts in an
empty sector, but then subsequent sectors in the series are used by another file, because
there is so much data being recorded, the disk drive does not have time to find, then move
to another area on the disk, so recording may stop.
This is not a problem with a completely empty disk, but if a sound file is deleted, the next
recording might start in the deleted space, and recording might stop because there is not
enough continuous empty sectors available. This will be more noticeable on a smaller hard
disk where you have to keep deleting unwanted sound files to make way for new
recordings.
The answer is to use a good hard disk defragmentation utility when a sound file has been
deleted. By defragmenting the disk, all sound files will be moved up to the front end of the
disk, leaving the available disk space as a series of continuous sectors at the end of the disk.
Hard disk partitioning
Because the CBX-D5 can read and write to any hard disk drive connected in the SCSI
chain, it is able to use individual partitions of a hard disk drive that has been partitioned.
However, the CBX-D5 cannot record across hard disks or partitions, so the available
recording time will be limited to the size of the partition.
NOTE: The time available for all recordings is not limited by the size of a hard disk
partition, it is the time available for one continuous recording, or one take
that is limited.
SECTOR
TRACK
FILE 1 FILE 2 FILE 3
6
SECTORS
10
SECTORS
8
SECTORS
FILE 1 FILE 4 FILE 3 FILE 5a FILE 5b
Space previously
occupied by file 2
FILE 5 has been
split – fragmented.