Mailing List Archive

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/

pgp key fingerprint = 79 2D DD 49 C0 AA D8 CF 2C F9 A5 6A BA 37 0E 28

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 :)

--
Mike Horwath Admin & Manager @ VISI.com WORK: drechsau@visi.com
IRC: Drechsau http://www.visi.com/ HOME: drechsau@geeks.org
The only Minnesota ISP with public statistics: http://noc.visi.com/
Garbage In -- Gospel Out. - berkeley fortune(6)

David Lee <t.d.lee@durham.ac.uk> writes:

> Anyone got any thoughts and/or experiences with UNIX /var/mail on NetApp?

My company is hosting a fairly large mail-system with several
Solaris based mailservers (pop/imap/smtp) all served from a single
F880 with close to 3TB of raw disks with no major systemic problems
at least regarding usage of NFS.

The words saying that NFS is problematic, is at best history, as I
have been in companies using NetApp's for mail-store for the past 7
years or so.

It may involve tuning nfs on the client side, we have not done much on
the netapp side - and ensuring that the network is able to handle the
expected traffic.

>>>>>>>>>>>>>>>>>>.rune

--
Rune Bakken
Senior System Administrator
Telenor Business Solutions (Nextra), Communications/IP-Services
Ph: +47 22 77 03 93

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
>

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

This is a good point. I know Solaris does this, possibly others. The
default Sendmail configuration on at least some versions of Solaris will
automatically try to use the server /var/mail is mounted from as the
mailhost for transferring outgoing mail. You should be able to override
this in the sendmail.cf.


--
Mike Sphar - Sr Systems Administrator
Remedy Corporation

-----Original Message-----
From: devnull@adc.idt.com [mailto:devnull@adc.idt.com]
Sent: Monday, September 30, 2002 1:04 PM
To: toasters@mathworks.com
Subject: Re: UNIX /var/mail on NetApp?

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
>

> ...snip...
> 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.

I'd like to echo those sentiments: I build mail systems - the
Maildir / NetApp combo means that my largest client currently
has a system with 1.6 million Maildirs ( = users) and it's still
growing nicely. I wrote to highlight qmail - "The original and best"
mailserver to use Maildirs. Qmail is a particularly strong mailserver
implementation and is very stable - I have some concerns with
Courier mentioned by Bennett in that a new version seems to
appear frequently.

The other nice thing about Maildirs is that because of their (as
Bennett says) "everything Just Works" design, you can have
multiple machines writing entries (messages) to the same
Maildir without their needing to be aware of one another's
existence; that really helps systems to scale.

More info on qmail at www.qmail.org and cr.yp.to/qmail.html

cheers,

Andrew.

2002-10-01-04:16:25 Andrew Richards:
> I wrote to highlight qmail - "The original and best" mailserver
> to use Maildirs. Qmail is a particularly strong mailserver
> implementation and is very stable - I have some concerns with
> Courier mentioned by Bennett in that a new version seems to appear
> frequently.

I followup only to mention that my choice of Courier applies only to
the IMAP (and POP) daemons (the Courier-IMAP package), and the
maildrop Local Delivery Agent, which work together to support a very
nice virtual user architecture around /etc/userdb.

For MTA, qmail is definitely one of my top two choices. I personally
prefer to use Postfix, but when making recommendations to others I
try to just advise them to use one or the other of those two,
whichever they like best.

This is wandering off-topic for the toasters list, I'm afraid; if
anyone wants to discuss MTA choices more, do please feel free to
drop me a note off-list. What can be said here with relevance is
that there are some of us who adore using NetApps as the heart of
big mail farms with Maildirs as the enabling data structure. If I'm
remembering aright, there was a tasty paper a few years back about
some large ISP (Earthlink, maybe?) who took this approach and came
away happy.

-Bennett

On Tue, Oct 01, 2002 at 09:16:25AM +0100, Andrew Richards wrote:
> The other nice thing about Maildirs is that because of their (as
> Bennett says) "everything Just Works" design, you can have
> multiple machines writing entries (messages) to the same
> Maildir without their needing to be aware of one another's
> existence; that really helps systems to scale.

Maildirs work very well.

> More info on qmail at www.qmail.org and cr.yp.to/qmail.html

Or if you want something that is easy to configure and has a
continuing history of development without the 'linux new version of
the day', check out Postfix (http://www.postfix.org/) which supports
Maildir format out of the box as well as mbox format allowing you to
'change' from one to the other when you are ready.

--
Mike Horwath Admin & Manager @ VISI.com WORK: drechsau@visi.com
IRC: Drechsau http://www.visi.com/ HOME: drechsau@geeks.org
The only Minnesota ISP with public statistics: http://noc.visi.com/
Garbage In -- Gospel Out. - berkeley fortune(6)

On Tue, 2002-10-01 at 14:09, Bennett Todd wrote:

> This is wandering off-topic for the toasters list, I'm afraid; if
> anyone wants to discuss MTA choices more, do please feel free to
> drop me a note off-list. What can be said here with relevance is
> that there are some of us who adore using NetApps as the heart of
> big mail farms with Maildirs as the enabling data structure. If I'm
> remembering aright, there was a tasty paper a few years back about
> some large ISP (Earthlink, maybe?) who took this approach and came
> away happy.

We're currently using an F760 mounted onto 20 servers for our mail
system. We use Courier (POP3) for the 10 reader boxes, and Exim4 for the
10 MTA boxes, obviously using maildir over NFS.

This setup is merrily handling around 5 million inbound emails a week.
We're very happy with maildirs on a netapp.

Jerry.
--
Supanet Ltd., Communications House,
Jeremy.Nicholls@supanet.net.uk
Shuttleworth Mead Business Park,
www.supanet.net.uk
Blackburn Road, Padiham, Burnley, Tel: +44 1282
681000
Lancashire, United Kingdom, BB12 7SN Fax: +44 1282
681001

We've been using the following auto_direct entry for mounting /var/mail on
Solaris 2.6, Solaris 8, and <cough> SunOS 4.1.3 clients for years without
incident:

/var/mail -rw,intr,hard,actimeo=0 toaster:/vol/fs0/mail_spool

However, we don't use the standard Sun Sendmail configs. either.