Arik Ashepa wrote:

> are there any?
>
> Arik
>
>
>
>
>------------------------------------------------------------------------
>
>Want to buy your Pack or Services from MandrakeSoft? 
>Go to http://www.mandrakestore.com
>
It depends on the filesystem for defrag.  Reiser, XFS, ext2 and ext3 
hardly need them because they set up files in such a way that 
fragmentation is kept very low.  (Look on the expert list archives for 
my article on this.)

JFS does have a defrag, and there is an old one for ext2 which worked 
usefully with the ext filesystem, but was hardly worth running with ext2 
(no speed gain).

All have a "scandisk" which has the generic name fsck (filesystems 
check).  Some of these are very very very quick, like 10 G in 3 seconds 
because they write a "journal" of what they are doing and simply play it 
back until it doesn't match, which is where they know it was left off. 
 (The journal is written to disk ahead of the actual disk operation). 
 Ext2 can take a while to do an fsck, but the fact that it scatters 
superblocks across the partition in which it is defined usually assures 
that glitches can be rebuilt without serious data loss.  Yes, even if 
the master superblock is corrupted, there are several backups.

ext3, XFS, Reiserfs, and JFS are called "journaling" filesystems and 
they have fairly high data integrity and fast rebuild times.  except for 
ext3, they are rather fast on everyday applications.  ext2 is an older 
filesystem equal in speed to journaling filesystems or even a bit faster 
in some circumstances.  Its major slowness is in rebuilding a big 
partition.  All 5 filesystems are built for facilitating the design and 
implementation of high security, and only JFS really allows 
fragmentation to occur.  My ext2 partitions have something like .17% 
fragmentation on the average and seem to hang right there regardless of 
how many files I add or take away.  With really radical test programs 
(forming and resizing 100,000 tinu files 2k to 10k in size, I managed to 
push fragmentation up to 3.13% but then it dropped when I deleted those 
contrived files.

Civileme




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