Fwd: Re: [Sussex] Why Linux doesn't need defrag

[Alan Pope]

On Thu, Aug 17, 2006 at 07:32:28AM -0600, linux at oneandoneis2.org wrote:
> Quoting Nic James Ferrier <nferrier at tapsellferrier.co.uk>:
> 
> >>I was under the impression that Linux has no clue about the real physical
> >>geometry of the disk because that's abstracted by the circuitry on the
> >>drive/controller. As far as Linux is concerned it's a large number of
> >>sectors, it has no clue *really* how they're arranged.
> >
> >That's right. I don't think any OS has access to this information
> >anymore.
> 
> Righto - I've edited the relevant section, thank you both!
> 

Of course.. (sorry about this)

Your guide doesn't take clusters into account. If a file is 4k and resides
wholey in an 8K cluster then if it grows by 2K it will still be inside one
cluster. Whereas if it grows more significantly then the filesystem driver
will go looking for the next available cluster (in windows).

You also don't mention that most of what you've said applies to FAT16/32 and
thus *does* affect Linux because we use media players, usb sticks and memory
cards that are formatted as FAT32.

Sorry for throwing this at you piecemeal.

Cheers,
Al.