John,
I looked at doing the same type of thing a while ago. Due to funding it was
scrapped, to do what I think you want to do. Let's just say this is not the
cheap solution.
What you want to do is setup the front end mail servers in a cluster for 1
IP address and hostname. Then get something like a Network Appliance for
the back end. The network appliance is the storage device that will hold
all of the email, users, logs, etc.... You then have 2 or more front end
servers that share the same settings and files. Which are stored on the
Network Appliance.
If you are running SQL. You will probably want to setup an SQL cluster.
(It's not cheap!) The cool thing about setting up a HA mail cluster like
this is it will scale. If you run out of drive space. Just add more Drive
shelf's to the Network Appliance. The Network Appliance scales to over a
Terabyte. If the mail servers start to get bogged down, add more servers.
The Net App will also hold your SQL database if you so desire.
There are a few other issues you need to look at and work out. One of which
is the registry settings. If you setup on W2k 1/2 of the battle for that is
done. That is one way to do it.
The another way is to setup Imail in an LDAP cluster. But it does not do
load balancing more like load sharing or parsing between servers for POP
accounts. It is more like you have users A-E on Server 1 and users F-N on
Server 2 and so on. Then the LDAP service finds the server where the POP
account is stored.
The last option is to have a hot standby server which you replicate all
changes to. Clustering technology for High Availability is getting a lot
better. Some HA cluster devices will real time image the servers for you
off a master server.
Good luck,
Mark
-----Original Message-----
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED]]On Behalf Of john miller
Sent: Thursday, March 15, 2001 2:28 PM
To: [EMAIL PROTECTED]
Subject: [IMail Forum] F5 Big IP and Imail
Hello All!
has anyone use f5 Big IP to load balance multiple IMail Servers? The SMTP
part is simple, it is the retrieval of email which I need to figure out. I
like a way to load balance POP3 also, but how would I ensure that all the
mail is retrieved, if running on different servers. The mail would be stored
on different severs, depending on which server retrieved the mail. Users
would only retrieve the mail that was on server has.
Thanks,
John Miller
----- Original Message -----
From: "Steve Zohn" <[EMAIL PROTECTED]>
To: "Daniel Donnelly" <[EMAIL PROTECTED]>
Sent: Thursday, March 15, 2001 9:17 AM
Subject: Re[2]: [IMail Forum] Redundant Send and Receive
> There is a product called Double Take from NSI software that does this
> type of thing well. I have not used it with imail, but have with SQL
> without problems. It handles the file sync, and IP switchover, I am
> not sure if it does the registry changes that would be needed.
>
> www.nsisw.com for more info.
>
>
> Regards,
> Steve
>
> DD> Hmmmm, this means one needs at least 2 SQL and 2 File servers, so
there is
> DD> redundancy (and cost!) in those.
>
> DD> The best method (modest cost and highest uptime) I can envision would
be to
> DD> have 2 duplicate machines and a switch over mechanism that puts the
second
> DD> server online when the first fails. Just need to tools to perform the
> DD> switchover and the duplication of the files and data from the primary
> DD> machine to the secondary. This means only one 'backup' email machine
and
> DD> some software to keep them synchronized. Seems that this would be a
less
> DD> expensive and less hardware intensive technique than Rick's.
>
> DD> Rick's method might be better for a system that already uses SQL and
maybe a
> DD> larger system, so it does have a place in this world. But for a
smaller
> DD> email system and less backup costs, I think my way may have some
advantages.
>
> DD> Using your existing S&F server, the total downtime would be the time
it
> DD> takes you to construct a new mail computer, install software and data
files.
> DD> I've done this in as little as 2 hours (1:50 was in copying the data!)
for a
> DD> modest sized server. If you already have the computer built and it has
> DD> copies of your \imail folders and files, the time would be reduced to
> DD> something like 10 minutes or so ( changing the IP/hostname, installing
IMail
> DD> and copying the registry). If your boss can live with that, then you
need
> DD> just the hardware and daily backup of your user data to the backup
email
> DD> machine. The second machine could actually serve 2 purposes!
>
> DD> Daniel Donnelly
> DD> ________________________________________________________
>
>
> DD> ----- Original Message -----
> DD> From: "Rick Marei" <[EMAIL PROTECTED]>
> DD> To: <[EMAIL PROTECTED]>
> DD> Sent: Wednesday, March 14, 2001 5:38 PM
> DD> Subject: AW: [IMail Forum] Redundant Send and Receive
>
>
> >> Hi,
> >>
> >> to guarantee imail 100% uptime for a large number of users , here is
how
> DD> to
> >> do it
> >>
> >> 2 imail servers authenticating against 1 clustered SQL Server and mails
> >> should be stored in 1 clustered file server to store emails, if this is
> DD> too
> >> much for you, just use RAID 5 or 10 for storing the mailboxes and also
for
> >> SQL
> >>
> >> the mail files could be moved easily to a new box and the forwarding
> >> information are stored in plain text files in the mailboxes
respectively
> >>
> >> for further details, please contact me
> >>
> >> Rick Marei
> >> i factory.at Internet Services GmbH
> >> Ferdinand Frey Weg 36
> >> A-1140 Wien
> >> Tel: +43 1 577 35 35
> >> Mobil: +43 676 95 666 11
> >>
> >> -----Ursprüngliche Nachricht-----
> >> Von: [EMAIL PROTECTED]
> >> [mailto:[EMAIL PROTECTED]]Im Auftrag von Yuri
Levenfeld
> >> Gesendet: Mittwoch, 14. März 2001 14:21
> >> An: [EMAIL PROTECTED]
> >> Betreff: Re: [IMail Forum] Redundant Send and Receive
> >>
> >>
> >> clustering mail server
> >>
> >> ----- Original Message -----
> >> From: Stephen LaBuda
> >> To: [EMAIL PROTECTED]
> >> Sent: Tuesday, March 13, 2001 1:08 PM
> >> Subject: [IMail Forum] Redundant Send and Receive
> >>
> >>
> >> Ok All, I am looking to implement some kind of redundancy for my mail
> >> service. Granted I already have a store and forward box but this
doesn't
> >> seem to meet the needs of the "boss" .. He wants 0 downtime or near
zero
> DD> as
> >> possible for both sending and receiving mail for our service.
> >>
> >> Any suggestions on going about this?
> >>
> >> Thank You
> >>
> >> Stephen
> >>
>
>
> DD> Please visit http://www.ipswitch.com/support/mailing-lists.html
> DD> to be removed from this list.
>
> DD> An Archive of this list is available at:
> DD> http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
>
>
>
> Please visit http://www.ipswitch.com/support/mailing-lists.html
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>
> An Archive of this list is available at:
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>
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