Re: [RFC] FSFS filesystem options (long, sorry)

On Mon, Mar 05, 2007 at 10:41:10PM -0600, Peter Samuelson wrote:
> Kean Johnston (CC'd) wanted this feature back in 2005 on the grounds
> that SCO Unixware had severe scalability problems when a directory
> exceeds 4096 entries:
>
> http://svn.haxx.se/dev/archive-2005-10/0269.shtml

Oh yeah, I remember that thread. "exponential degradation for each
multiple of 4096 inodes".

>
> I guess I'd vote for 2000 entries per bucket. Honestly, 1000 entries
> is probably sufficient - you have to go north of 2000000 revisions
> before it scales worse than 2000 entries.

A power of ten is probably useful for that purpose, but I'd like to go
with buckets of at least 4000 entries. That's not too high that any
reasonable filesystem should have problems, but it leaves enough space
for large repositories to grow into.

And yes, I'm aware that I'm effectively considering repositories with
16M revisions as 'large' there :-)

Regards,
Malcolm