[plug] usb storage howto

[Kev]

Arie Hol wrote:

> FAT16 will go to a maximum size of 2Gb - maximum of 65,525 clusters with 
> a  size = 32,768 bytes
>
> Multiplying the maximum number of clusters (65,525) by the maximum 
> cluster size (32,768) equals 2 Gb. 
>
> FAT32 will go to a maximum size of 4Gb - maximum of 65,525 clusters with 
> a  size = 65,525 bytes
>
> Multiplying the maximum number of clusters (65,525) by the maximum 
> cluster size (65,525) equals 4 Gb. 
>
> Although - FAT16 can become inefficient with files sizes greater than 
> 64Kb.

I always understood FAT becoming inefficient with small file sizes, not 
large.  Bear in mind that the smallest amount of space a file can 
consume is 1 cluster.  Therefore a 1 byte file on a 2g FAT16 partition 
will still consume 32,768 bytes of disk space.  With large files, each 
cluster which the file occupies, except the last cluster, is filled to 
capacity (so to speak) and the only wastage is in the final cluster.  
Hence /much/ more efficient use of space.  All file systems have their 
equivalent to clusters.  ie they have a minimum storage unit size.  Most 
good file systems allow you to manually set the 'cluster' size, so as to 
optimize disk usage for particular situations.  IBM's HPFS was one of 
the early /very/ good file systems, with a default cluster size of 512 
bytes, manually changed if the user wished to do so.   ReiserFS and ext3 
(I think) both use 4096 bytes as their default cluster size, but this is 
also manually changed if the user wishes to do so.

I think that stuff is correct.  At least it was once ;-)

Cheers
Kev


-- 
=======================================================================
Kev Downes
kdownes at tpg.com.au  ph 0404 7 0808 2
We use and recommend Xandros 4.0.0
=======================================================================
There are 10 types of people ...
   ... those who understand binary, and those who don't!
=======================================================================
"Jesus Christ is the centre of everything and the object of everything;
He who does not know him, knows nothing of the order of the world
and nothing of himself."             Blaise Pascal
=======================================================================