Re: Mailbox Hashing

[Imre Fitos <btv@danger.island.one.net>]

On Tue, Apr 04, 2000 at 03:58:49PM +0000, Dan wrote:
> How can hashing be implemented for /var/spool/mail/* files? Users we'll be popping
> their mail as well as acessing with web-client.

mail is usually store din the user homedirectories in a subdirectory or a file
(i use .mailbox) so the whole home directory structure is hashed. procmail
and cucipop supports it (almost) out of the box.

> 
> >On Tue, Apr 04, 2000 at 03:12:03PM +0000, Dan wrote:
> >> How would Zmailer's performance be effected if it hashed mailboxes, or stored
> 
> >> them in Maildir format? How do large mail spool files affect Zmailer? Or
> those
> >> problems are alieviated with the help of router? What would be the maximum
> number
> >> of users supported by FS without mail spool hashing. These are very interesting
> 
> >> questions. Any ideas? Thanks.
> >> 
> >> This Free Email is provided by http://www.docisp.com
> >
> >I think that question pertains to zmailer's local mail transport program, sm.
> 
> >It also depends a lot on the underlying OS and the filesystem. I know
> >SGI's XFS hashes the directories anyway so you don't get a slowdown
> >in a flat structure. I run Linux and ext2 so it was necessary to hash.
> >
> >I always used procmail in the place of sendmail as our users have .procmailrc
> 
> >files so I don't know the reason for that, but I do know that around 
> >8 thousand users mounted through NFS it gets painfully slow. We switched
> >to two-level hashing and now we're at 25 thousand users and it still rocks.
> 
> >my next project is building an even bigger mailfarm that can scale up
> >to a million users, most likely using three levels of hashing.
> >
> >Imre
> >