[Dovecot] maildir on zfs (was: mailbox format w/ separate headers/data)

[Frank Cusack]

On January 22, 2010 9:03:42 PM -0500 Charles Sprickman <spork at bway.net> 
wrote:
> Sorry for the tangent,

You should probably start a new thread when changing the subject.  Then
you don't have to be sorry. :)

> but I wonder if anyone here is running lots of Maildirs on zfs?

When you say "lots of Maildirs" I assume you mean filesystem-per-user?
You can of course use "lots of Maildirs" yet have only a single zfs
filesystem but that doesn't seem to me to be worth questioning.

I am running that way but it's less than 100 users so probably not what
you would consider "lots".

> I'd seen some comments here in the past that zfs+maildirs = bad.

I can't imagine why that would be the case.  There are some problem
loads for zfs (zfs-backed NFS writes, e.g.) but why maildir would be
particularly singled out I wouldn't know.

For filesystem-per-user, if by "lots" you mean 1000 or 1000s then you
have the problem that it takes forever to mount all of those filesytems
on reboot.  That's not a maildir-specific problem though.

-frank