We run a fairly traditional UNIX email service: delivery to a Solaris-8 machine with sendmail, hosting the "/var/mail" mailstore. The operations on the mailstore files themselves are entirely from the Washington suite: POP/IMAP server (clients) and their "tmail" (sendmail 'Mlocal' delivery). There is no direct NFS access to the mailstore.
One of the pieces of received wisdom is that the "/var/mail" mailstore should not be accessed by NFS, as NFS is (they would say) notoriously problematical. I'm inclined to believe this.
Nevertheless, we are toying with the idea of putting "/var/mail" onto a NetApp thereby, of course, introducing NFS and its locking into the equation. Naturally, we are rather wary of doing this. But, if done, its major advantage for us would be in allowing us to set up an expandable "farm" of modest-size IMAP/POP machines, rather than having to run it all on one major machine.
Anyone got any thoughts and/or experiences with UNIX /var/mail on NetApp?
David,
we store /var/mail on NetApp filers (F840c, F760c) at several sites with diffeent size (12 to 200 Sun Solaris 2.5.1/7/8/9 clients) without problems.
we automount /var/mail in /etc/auto_direct with these options:
/var/mail -rw,hard,intr,noac,actimeo=0 filer:/vol/vol1/qtree04/mail
we do use POP3, but most clients access the mailbox via NFS directly.
Hope this helps
--pwo
-- Peter W. Osel Principal - Development Systems Infineon Technologies Email: pwo@Infineon.COM North America Corp. Phone: +1 (408) 501 6321 1730 North First Street Fax: +1 (408) 501 2410 San Jose, CA 95112, USA WWW: http://pwo.de/
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here is what we do in /etc/auto_direct
/var/mail -rw,hard,actimeo=0 filer:/vol/vol2/mail
intr, hard are defaults. You might want to add noac.
This is not the right way of doing things(over nfs that is). If your people complain about not getting mail on the client, do a /usr/lib/sendmail -v you@yourdomain.com
You might see it trying to make a port 25 connection to your filer :) Again, that is not a NetApp thing, more of a /var/mail over NFS thing.
Thanks.
David,
we store /var/mail on NetApp filers (F840c, F760c) at several sites with diffeent size (12 to 200 Sun Solaris 2.5.1/7/8/9 clients) without problems.
we automount /var/mail in /etc/auto_direct with these options:
/var/mail -rw,hard,intr,noac,actimeo=0 filer:/vol/vol1/qtree04/mail
we do use POP3, but most clients access the mailbox via NFS directly.
Hope this helps
--pwo
On Mon, Sep 30, 2002 at 05:41:43PM +0100, David Lee wrote:
We run a fairly traditional UNIX email service: delivery to a Solaris-8 machine with sendmail, hosting the "/var/mail" mailstore. The operations on the mailstore files themselves are entirely from the Washington suite: POP/IMAP server (clients) and their "tmail" (sendmail 'Mlocal' delivery). There is no direct NFS access to the mailstore.
One of the pieces of received wisdom is that the "/var/mail" mailstore should not be accessed by NFS, as NFS is (they would say) notoriously problematical. I'm inclined to believe this.
Nevertheless, we are toying with the idea of putting "/var/mail" onto a NetApp thereby, of course, introducing NFS and its locking into the equation. Naturally, we are rather wary of doing this. But, if done, its major advantage for us would be in allowing us to set up an expandable "farm" of modest-size IMAP/POP machines, rather than having to run it all on one major machine.
Anyone got any thoughts and/or experiences with UNIX /var/mail on NetApp?
It does work as long as all of your clients can do locking.
But it is not as fast as you might be hoping for :(
What we did was move away from mbox format mailboxes into Maildir format mailboxes which removes locking issues.
Works very very well, but unfortunately, if you do not want to change software, this won't be a solution for you.
We ran /var/mail on an F720 years ago and it worked until we saturated the poor F720. Took about 3 months :)
As others have said, with care, you can move a /var/spool/mail store of mbox-format folders to a NetApp; yes, it introduces NFS, which has problems with locking, but NetApps are some of the more skilled and competant NFS talkers:-). Make sure you don't have NFS-related problems with the hosts that mount the /var/spool/mail, make sure they're all locking well and take care with parameters, and it can work.
If you want to go this route, I'd recommend a testing period during which you occasionally yank the network cables into your netapp, and occasionally pull the power, of the netapp, and of your mail server[s]; recovery after such incidents is where NFS locking really has the worst problems, and you want to learn all about it in testing. Make sure you're really loading the system while you're doing these failure tests.
Once you move into prod, of course make sure your netapps and your servers are all provisioned with the most reliable power you can, often that's UPS, so you don't have to worry about exercising this stuff as often.
If you can direct all your mail client accesses through IMAP or POP, leaving no programs but the delivery agent and the imap/pop daemon doing direct mailbox accesses, then you get the ability to relatively painlessly change mailbox formats. That's worthwhile; Maildir+NetApp is one of the sweetest spots in the whole mail server design spectrum. Forget locking, forget recovery, everything Just Works.
When I build a server, even if it's a single box for everything, I go with maildrop delivering to virtual user Maildirs, with Courier-IMAP (which offers pop, and the /ssl varients) providing access for MUAs; this sets me up to grow as big as ever I could want and never worry about mailbox correctness.
-Bennett
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Bennett Todd -
David Lee -
devnull＠adc.idt.com -
Mike Horwath -
Peter W. Osel