[P1] Defragmentation method/DiskWarrior

Richard McKay richard.mckay1 at virgin.net
Mon Nov 10 06:33:06 PST 2003


Jack Rodgers wrote the following:

> 
> On Nov 10, 2003, at 12:00 AM, Jay Boshara wrote:
> 
>> In other words, what exactly does the Directory
>> contain?
> 
> It contains points to the beginning and ending of the fragments of
> files. The segment size of a part of a file is about 6K or less. Thus
> large files are composed of many segments on the hard drive. These
> segments are not necessarily in order and may be scattered about the
> drive. Since there are many small segments, pre-hfs drives had segment
> sizes a hundred times larger and thus less fragmentation, the directory
> has to track each one. The directory itself can become fragmented as
> files are rewritten or portions deleted.

Not sure if anything is deleted from the directory? As I understand it, the
move of a piece of data from a to b is added to the information of where it
is now located (b), but the old information (a) is not removed (it is just
not valid anymore). In this way, only when you rebuild a directory would the
latest location of the data (b) be listed (such as when you use DW) thereby
saving potential trouble (if you have moved a lot of files around several
hundreds of times) and time (only one entry initially and not having to go
through the list of it was here and then here and is now here). Have I
misunderstood something?

Additionally the files themselves are still scattered around the drive and I
would have thought that the defragmentation of the files would be of great
space and speed interest. For this you would need another utility such as
the earlier DW or Norton or others that were mentioned...

Richard
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