[Summary] Mail Server Plan & SDS 4.0

From: Chi Man Wu - SAN (wuc@hkmail.sps.mot.com)
Date: Thu Jul 10 1997 - 06:09:59 CDT

Dear SM,

        Sorry for my late summary. Thanks for following

        David M. Davisson <davisson@emuni.com>
        David Fetrow <fetrow@biostat.washington.edu>
        Greg Ness <nessgr@cit.org>
        Jim Harmon <jharmon@telecnnct.com>
        Kevin Sheehan <Kevin.Sheehan@uniq.com.au>
        Michael Pavlov <misha@ml.com>
        Tom Jordan <Thomas.Jordan@East.Sun.COM>
My Question:
        In my department( Sparc, Solaris 2.5.1), only one
        mail server, all other workstation mount their
        /var/mail from mail server.

        My qyestion, in case the mail server down,
        all workstation will hang.
        How can I avoid this ??

        Furthermore, I plan to install SDS 4.0 on
        this mail server, hope more reliable ..
        What different between SDS4.0 and SDS4.1 ?
Answer :

David M. Davisson <davisson@emuni.com>
Don't mount /var/mail at clients. You should be running sendmail with a POP3
host program so that users can retrieve their mail privately and in a secure

David Fetrow <fetrow@biostat.washington.edu>
One possibility is using pop (or better: imap) to retrieve email
instead of NFS....email is delivered to the user only when they ask
for it rather than having the email disk mounted all the time.
See http://imap.cac.washingon.edu/

 Another is to use automounter for /var/spool/mail

 Another is to restrict mail clients to a single machine; the machine
with /var/spool/mail.

Greg Ness <nessgr@cit.org>
        Sounds like you have the clients doing a 'direct' mount of their
/var/mail directory. I would try an 'indirect' mount or link.


Jim Harmon <jharmon@telecnnct.com>
Change the NFS mount information for teh /var/mail dir to SOFT and
AUTOmount, so that the systems won't crash if the NFS export fails.

Kevin Sheehan <Kevin.Sheehan@uniq.com.au>
By replicating the data in /var/mail via the network. We have a product
called UPFS that does exactly this. Check out our web page at
http://www.uniq.com.au, or you can mail us on upfs-info@uniq.com.au
for more information.

Michael Pavlov <misha@ml.com>
Using automounter with configured NFS client automounter failover
might do the jobs.
Another thing to look into is round robin DNS lookup and MX records.

Please summarize.

BTW. what's SDS ?

Tom Jordan <Thomas.Jordan@East.Sun.COM>
You can mount /var/mail with a timeout option or mount it "soft" instead of
"hard". Look at the mount manpage for the options.

It is my impression that 4.1 is more stable than 4.0,
but I don't think that there are major changes. I think 4.1 is basically
4.0 with some patches.

My Feedback :
Option 1) Using pop3/imap for receive email, but most of our user still using
        mailtool and Zmail

Option 2) Use automount and soft mount. But from man page (below), I not
        recommend use soft mount.

        File systems that are mounted read-write or that con-
           tain executable files should always be mounted with the
         hard option. Applications using soft mounted file sys-
         tems may incur unexpected I/O errors.

        My finial dicision is use auto mounter and auto_direct, option is
        /var/mail -rw,soft,noac,actimeo=0 mail-server:/var/mail

Best regards,
Man Wu

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