you could try a load balancer with virtual ip to which pop3.domain and
smtp.domain point, and two servers behind that, one of which is the primary
(referenced in the load balancer) and the other the secondary
(unreferenced), and the secondary pulling differential copies of the data
off each hour (??)) when the primary went down, change the load bancer
config (takes about 5 seconds) and up comes the secondary with a copy of
backup mail etc etc ... we've experimented with such a setup and it works OK
for low volumes of mail only (in which case you might not want to go out and
spend 12K on a Foundry). Larger quantities of mail becomes quite difficult
because of the volume of data that needs to be transfered in a single backup
run for the secondary.
there are lots of catches, but its workable, probably depends on how much
infrastructure and network engineering support you have at your disposal
baden
> -----Original Message-----
> From: Todd Lahman [mailto:[EMAIL PROTECTED]]
> Sent: Friday, 6 April 2001 8:51 AM
> To: [EMAIL PROTECTED]
> Subject: Re: [IMail Forum] Imail failover
>
>
> There is a way you could get a backup IMail server sort of.
>
> You can write a script on the main server which backs up the
> registry file
> using a command line. You schedule it to run every 24 hours
> or every hour
> depending on your needs. You then write a script to ftp that
> file to the
> backup server after each backup. You time it say 5 minutes after the
> registry backup is scheduled. On the backup server you use
> the same command
> line script to restore the registry on the backup server
> which will load in
> any changes from the main server. The only problem is if the
> main server
> fails the mail accounts will operate normally, but there
> won't be any mail.
> Copying the mail folders would take forever even with just a
> few hundred
> accounts. If you have an Access database you can also use
> the same ftp
> script to transfer and overwrite the backup server's database as well.
> Other than that there isn't a lot of failover I know would be
> guaranteed,
> and IMail isn't cluster aware.
>
> This script can also be used to simply backup your server to a remote
> machine offsite daily to make sure you still have a backup if
> there is ever
> a fire.
>
> ----- Original Message -----
> From: "Len Conrad" <[EMAIL PROTECTED]>
> To: <[EMAIL PROTECTED]>
> Sent: Thursday, April 05, 2001 12:30 PM
> Subject: Re: [IMail Forum] Imail failover
>
>
> >
> > >Just out of curiosity. Is the correct way to make a IMail
> backup server
> > >just to set up another machine running Imail, possbily
> synchronize the
> > >databases on both a couple time/day,
> >
> > That's pretty hard since the "database" of mailboxes is
> updated every
> minute.
> >
> > >and create an mx record with a lower priority number for the backup
> machine??
> >
> > The backup SMTP delivery only, not mailbox backup
> >
> > >or is there a better way? Also,
> > >how do you make a backup smtp server?
> >
> > RT, uh, read the explanation in the imail manual
> >
> > Len
> >
> >
> > http://MenAndMice.com/DNS-training : In Austin, TX; SFO, CA; Paris,
> > FR
> > http://BIND8NT.MEIway.com : ISC BIND 8.2.3 "NT3" for NT4 & W2K
> > http://IMGate.MEIway.com : Build free, hi-perf, anti-abuse
> mail gateways
> >
> >
> > Please visit http://www.ipswitch.com/support/mailing-lists.html
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> >
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> >
>
>
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