[OpenAFS] mail spool on AFS

[Derek Atkins]

"Enesha Fairluck" <enesha@sunflower.org> writes:

> There is a misunderstanding...We do provide imap, you just said to have all
> users use it, which can't happen right now:P  I assume tho that you were
> really refering to use from unix via pine or something?

What I meant was have all users use some mail client that accesses
mail via some network mail protocol (IMAP, POP, HTTP).  No user or
user-client application should access /var/spool/mail directly.

> > Any solution with a distributed /var/spool/mail just will not
> scale.
> 
> Why would it not scale?  I was toying with the idea of making each users
> mail file in that directory a volume and then load balancing across multiple
> servers, and being able to enforce a different quota for mail than for the
> standard files.

Because you cannot have replicated read-write volumes, basically.  You
are adding the complexity of AFS for zero (or near-zero) gain.

How it works at mit: Each user is assigned a particular Mail Server.
All mail gets delivered to the centralized set of mail servers and
then gets deposited locally on the mail server for the particular
receipient.  The recipient uses one of many mail clients to pull the
mail off the mail server and deposits it into their AFS home
directory.

The Mail Server provides a quota for how large the mail spool can be
for a particular user.  Similarly, each user has an AFS quota.  The
two are not necessarily related.

> So something like ~/mail/INBOX would be a workable solution?  Then having to
> tweak and or recompile pop3/imap/etc?

Well, it depends -- who puts the mail into ~/mail/INBOX?  If the mail
server, then no, I do not consider it workable.  If the mail client
(pine, GNUS, your-favorite-mail-client, etc) pulls the mail off the
mail server and stores it in ~/mail/INBOX, yes, that is perfectly
workable.

> Excerpt from "afs-faq" on faqs.org: (not the whole section)
[snip]
> Seems to recommend NOT using a dedicated mail machine, but putting into
> $home/mail or someplace, and indicates that the dedicated mail server
> doesn't scale very well.

This FAQ is old and incomplete.  They also leave out the ability to
access mail via POP/IMAP/etc.  Going back to the MIT solution, this is
a modified scenario 1 however users never log into the mail servers;
they access them via mail clients.

I hope this explains what I mean,

-derek

-- 
       Derek Atkins, SB '93 MIT EE, SM '95 MIT Media Laboratory
       Member, MIT Student Information Processing Board  (SIPB)
       URL: http://web.mit.edu/warlord/    PP-ASEL-IA     N1NWH
       warlord@MIT.EDU                        PGP key available