Edward, Afaik the most commonly used smtp server implementations do support this type of setup. I agree its not required, but highly encouraged by the authors of the rfc. >From RFC 974 ( http://www.faqs.org/rfcs/rfc974.html ): <lawyerly quoting> " If the list of MX RRs is not empty, the mailer should try to deliver the message to the MXs in order (lowest preference value tried first). The mailer is required to attempt delivery to the lowest valued MX. Implementors are encouraged to write mailers so that they try the MXs in order until one of the MXs accepts the message, or all the MXs have been tried. A somewhat less demanding system, in which a fixed number of MXs is tried, is also reasonable. Note that multiple MXs may have the same preference value. In this case, all MXs at with a given value must be tried before any of a higher value are tried. In addition, in the special case in which there are several MXs with the lowest preference value, all of them should be tried before a message is deemed undeliverable." </lawyerly quoting> In any case, I would consider myself a negligent admin should I opt to implement corporate mail infrastructure without having a backup mx host (preferably in different locations). -Tobias -----Original Message----- From: redhat-list-bounces@xxxxxxxxxx [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Edward J. Weinberg Sent: Wednesday, April 28, 2004 4:56 AM To: General Red Hat Linux discussion list Subject: RE: Disaster recovery recommendations for RH Linux 8.0... On Tue, 2004-04-27 at 14:15, Tobias Speckbacher wrote: > The smtp protocol offers you to set backup mx records via dns. > This will cause the sending server to try all of these before giving up > on delivery. (should the server in question be your MX host). Quick > search yielded http://www.dyndns.org/support/kb/mxrecords.html on this > topic. Might do that. You need to think like a lawyer. The RFC says you CAN try other MS records, not that your mail server MUST try them. Some mail servers do and some don't. Your reference supports this: "In addition to specifying the mail server which should receive mail for a domain, MX records can also specify the host(s) to which mail can be delivered if the primary mail server is off-line." CAN be delivered is different from MUST be delivered. That means that some email might be delivered to the secondary MX. > I would definitely set up the system with 2 drives in a raid 1 > configuration. If you can afford it go for hardware raid, otherwise use > the md feature in RH. > > http://www.tldp.org/HOWTO/Software-RAID-HOWTO.html > > -Tobias > > -----Original Message----- > From: redhat-list-bounces@xxxxxxxxxx > [mailto:redhat-list-bounces@xxxxxxxxxx] On Behalf Of Ed Wilts > Sent: Tuesday, April 27, 2004 6:29 AM > To: General Red Hat Linux discussion list > Subject: Re: Disaster recovery recommendations for RH Linux 8.0... > > On Tue, Apr 27, 2004 at 10:07:31AM -0400, Ken Morley wrote: > > I have a RH Linux 8.0 server used to filter email for spam and virues. > It > > receives email, filters it through SpamAssassin and ClamAV and then > relays > > the email to our Exchange server. The email is only on the server for > a few > > seconds. > > This is what we do here. The way we've solved it is to run 2 RHL > servers and have DNS records that round-robin between them. If either > system fails, the other will take 100% of the load, but on average, each > system takes half the load. > > > Can anyone recommend a simple, inexpensive solution that would allow > me to > > image the hard drive periodically and quickly restore to a replacement > hard > > drive? I'm thinking that the backup media would probably be CD-ROM > (the > > entire installation is only about 800MB uncompressed). > > http://www.mondorescue.org > > -- > Ed Wilts, Mounds View, MN, USA > mailto:ewilts@xxxxxxxxxx > Member #1, Red Hat Community Ambassador Program > > > -- > redhat-list mailing list > unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe > https://www.redhat.com/mailman/listinfo/redhat-list -- Edward J. Weinberg <edw@xxxxxxxxxx> -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list -- redhat-list mailing list unsubscribe mailto:redhat-list-request@xxxxxxxxxx?subject=unsubscribe https://www.redhat.com/mailman/listinfo/redhat-list
