[clue-tech] Why is rm so slow?

[Angelo Bertolli]

David L. Willson wrote:
> I think this is the relevant bit.  Why do deletions on FAT and NTFS go off instantly and
> EXT* removals take time in direct proportion to file-size?  Is there a fundamental
> difference in how the filesystems work?  If so, what benefit are we getting for the
> overhead?
>
>   
Yes, definitely they function differently.  I'm not that familiar with 
how NTFS works, but not all filesystems are equal:  some can be mostly 
(or strictly I guess) better than others.  In the case of FAT you don't 
even have a journal:  that alone should make it faster in most cases I 
would think.  (But if you pull the plug on your system, you risk being 
in an inconsistent state.)

I looked at some benchmarks when you brought this up, but none of them 
tested based on the size of file that I saw, so I didn't have any 
information for you.  I don't know how close ext3 is to UFS, or how it 
uses inodes, but I always kind of assumed they were pretty similar.  I 
don't know if ext3 has to free up each pointer to blocks of data 
(assuming it's like UFS) or how it stores used vs non-used blocks.  In 
the case of FAT, I guess it just has to mark those locations as "not 
used" in the gigantic table at the beginning of the disk that remains 
static.

Angelo