defrag

[jekillen]

On Mar 1, 2007, at 2:56 PM, Ivan Voras wrote:

> Lowell Gilbert wrote:
>
>> If you know the standard computer science terminology, it can be
>> described quite tersely.  UFS fragmentation is a way of avoiding
>> internal fragmentation from wasting too much space.  MS-DOS-FS
>> fragmentation is an example of external fragmentation in the storage
>> space.  They don't really have anything to do with each other.
>
> It looks like I actually AM arguing about semantics here:
>
> 	"UFS fragmentation" refers to dividing blocks (e.g. 16KB in size) into
> block fragments (e.g. 2KB in size) that can be allocated separately in
> special circumstances (which all boil down to: at the end of files).
> This is done to lessen the effect of internal fragmentation.
>
> 	"Fragmentation" without "UFS" prefix, as mostly used today (and which 
> I
> believe it's how the original poster understands it) refers to dividing
> files into non-continuous regions, i.e. external fragmentation.
>
> Correct so far?
>
> "% fragmentation" message from fsck cannot refer to internal
> fragmentation as the numbers don't add up, so it almost certainly 
> refers
> to external fragmentation.
>
This discussion has been about UFS vs MS file system. But I have been
using Macs and have run file system utilities, Norton, and watched it 
defrag
a Mac disc. I am just curious as to how the HFS and HFS+ file systems 
fit
into this picture. Particularly since OSX is essentially a Unix 'like' 
system
but still uses HFS+
Just for some perspective and idle curiosity.
Thanks
Jeff K