[Dovecot] New mailbox format

[Jack Bailey]

Todd Vierling wrote:

>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.

>Other options now exist that improve this quite a bit.  On Linux, there's
>reiserfs; on BSD, there's lfs, and some enhancements to ffs as part of the
>"FFSv2" project.
>  
>

Last I heard Reiser was dropped by RedHat.  It's still an option on some 
Linux distros, e.g. CentOS.