[Dovecot] New mailbox format

[Jack Bailey]

>>> It mostly has to do with the filesystem being used.  The System V based
>>> extended filesystems (which most people know as "ext2" and "ext3") 
>>> have the
>>> same history as the BSD filesystem ("ufs" or "ffs"), and neither is
>>> particularly efficient at handling a directory of more than 10k 
>>> files or
>>> so.
>>> And it's not usually the lookup of a single file that's a problem; it's
>>> listing the directory (when doing index synchronization) that will 
>>> be slow.
>>
>> ext3 directories are hash databases, much faster than linear
>> searches/listings.
>
>
> not by default. it's a currently very-beta extension to ext3.


My understanding is that it's enabled by default for kernels 2.6 and 
up.  I'm running 2.6.9-11.ELsmp, it's ext3, the directories are hash 
trees, and I did nothing special during the install.

To Dean's point about older stuff, true.  There are probably a lot of 
2.4 kernels out there.