On Wed, Jul 31, 2002 at 06:46:55PM +0200, Ralf Hildebrandt wrote:
> > however, this is the dreaded mailbox on nfs issue. do procmail and mutt
> > play nice on nfs?
>
> If you use Maildir, yes.
Maildir has the problem of trading NFS locks for excess synchronous
meta-data operations, and synchronous meta-data operations are
something not dealt with well by most NFS servers (at least, anything
short of Auspex, EMC, or NetApp).
There are alternative solutions.
For POP3-based systems, Nick Christenson led the way in his
"Earthlink" paper, _A Highly Scalable Electronic Mail Service Using
Open Systems_, which you can find at
<http://www.jetcafe.org/~npc/doc/mail_arch.html>. IIRC, they used file
creation tricks (just like Maildir does), but instead of breaking out
each message into a separate file, they used the v7 "mbox" file
format.
You still have some synchronous meta-data issues to deal with, but
not nearly on the scale of Maildir, and even those can be at least
partially addressed (start with
<http://www.shub-internet.org/brad/papers/dihses/lisa2000/sld065.htm>
of my invited talk _The Design and Implementation of Highly Scalable
E-mail Systems_, which I presented at LISA 2000).
For IMAP-based systems, you would need to use the message store
engine from MessagingDirect (they hacked Cyrus so as to pull the
locking out of the filesystem and into an NFS-friendly database).
Alternatively, you would need to hack Cyrus to pull the file locking
out into an NFS-friendly database.
You may also be interested to read the book _Sendmail Performance
Tuning_ by Nick Christenson -- to be published on September 20, I
believe. While the title of the book is about sendmail, I believe that
it covers more than just this one program.
Disclosure: I was a technical reviewer of this book and Nick was my
co-author for the talk I gave at LISA 2000, so I may be a bit biased.
;-)
--
Brad Knowles <[EMAIL PROTECTED]> Senior Consultant for Snow bv
ASM Lithography bv + ITM&S Unix Competence Center + Room 02.D.2085
De Run 1110 + 5503 LA Veldhoven, NL + GSM +31 654 344 596
