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Defragmentation
Defragmentation:
Defragmentation is one of the best
ways to increase system performance. Disk fragmentation means the
storage of data is on physical disk in non contiguous locations
and scattered through on the disk. The inability of the physical
medium to provide contiguous storage is called as fragmented
storage. The inability of storage controller causes two types of
disk fragmentation, external and data fragmentation.
External fragmentation:
When the system turns to store a file
in the physical location, the physical location may not have
enough contiguous space to store that file. In that case the file
is stored in non contiguous location. Sometimes when users delete
files from the disk it may cause a free space in between files.
Such fragmentation is referred to as external fragmentation.
Internal fragmentation
Internal fragmentation occurs
frequently due to some type of failure of the file system store
files in-between the storing process. This mostly happens while we
cancel the copying of large files during. The file may be left
undeleted but occupies more memory than the copied content. This
is not considered a major problem but occupies unnecessary space.
Into our Hard Disk:
Let’s say for a sample that we are
going to store a file of 5 MB. This file may be located anywhere
because the sample disk is using 2048 byte clusters, so totally
2,560 clusters are needed. So these clusters may be on different
platters and tracks of the disk. Our computer is made of
electronic devices which can deliver responses at the speed of
electrons, but our hard disk is just a mechanical device where it
consumes time to move its head from one place to another. So this
seeking time increases if the file is scattered on the disk and
slows our system performance.
We cannot force our system to store
files in a contiguous location. But we can rearrange the files to
contiguous location. This type of rearranging a file scattered as
clusters into consecutive locations is simply called as
Defragmentation. Because when a file is rearranged in consecutive
locations the head movement is decreased by less seeking between
platters and tracks.
Tools:
In windows, two file systems are most
commonly used. They are FAT32 and NTFS. Windows 98 supports the
FAT file system and the defragment tool build-in with the OS gives
good performance. The other third-party tools are JKdefrag,
smartDefrag, ultraDefrag; speeDefrag can also defragment the disk.
But windows 9x build-in defragmenter is often the best to use.
Windows NT version includes a newer
file system called NTFS. The superiority of NTFS disk management
capability causes less fragmentation. In earlier releases of NT
versions they didn’t include any defragmenter. But the truth is
the complexity of file management in NTFS is very much cause for
different ways of fragmentation. Since FAT uses simple cluster
based storage the Defragmentation is simple and easy to defragment
it. In NTFS system the storing of file cause less fragmentation
but the addition and removal of data causes more fragmentation.
The NTFS uses a MFT (Master File Table) for keep track of file
storage. The addition or removal of data from file causes the MFT
to grow and causes fragmentation which reduces the performance
further.
For Windows NT the popular utility
called diskeeper by Executive Software is the best tool in my
opinion to defragment the disk. On its wisdom, Microsoft licensed
diskeeper and includes it in windows 2000. But the version
included is less capable and slower than the full version of the
diskeeper. So it is best to use the Diskeeper full version from
Executive software to increases the performance of the system. The
other third-party tools are Norton Utilities for NT, Perfect Disk
2000, O&O Defragmentation, and VoptNT. |
