Re: Unresolved issues #2 (shallow clone again)

> 
> 
> On Sun, 7 May 2006, Theodore Tso wrote:
> >> 
> > If there are 233338 objects, then the average wasted space due to
> > internal fragmentation is 233338 * 2k, or 466676 kilobytes, or only
> > 36% of the wasted space.
> 
> That's not necessarily true.
> 
> That assumes a randomly distributed filesize. File sizes are _not_ random, 
> and in particular if you have the distribution leaning towards <2kB being 
> common, you can actually get >50% fragmentation.
> 
> Btw, I hit this when some people argued that the page size should be made 
> 64kB. The above (incorrect) logic implies that you waste 32kB on average 
> per file. That's not true, if a large fraction of your files are small, in 
> which case you may actually be wastign closer to 60kB on average from 
> using a big page-size, because about half of the kernel files are actually 
> smaller than 4kB (or something. I forget the exact statistics, I did them 
> with a script at some point).
> 
> Anyway, with inode overhead and a lot of objects being just a couple of 
> hundred bytes, I think I estimated at some point that you actually lost 
> closer to 3kB per object.