Hi all I'm trying to build a redundant mail system using qmail-ldap. The idea is to have 1 primary server and a secondary one which could take over in seconds or even work as a secondary MX.
Primary server will be handling pop3 and imap. Servers would be using same ldap directory. When a primary server gets an email it delivers it locally and sends a copy to the secondary server using qmpc and maybe some hack in qmail-queue or qmail-local. Secondary server keeps these messages in some kind of log of incoming messages, so they can by later reinserted to the queue by some script and qmpc. When secondary server receives an email, it adds it to the log of incoming messages and delivers it to primary server using similarly patched qmpc, or queue. So we get a file or files with all the incoming messages on secondary and real delivery done only on primary server. When primary server dies all we need to do is reconfigure secondary to deliver incoming messages locally, not forward it to now defunct primary server, run a script to inject all the messages from the incoming messages log on secondary server that now is becoming primary and change ip for pop3 imap traffic. Of course clients will see all todays email delivered again (pop3 clients) or marked again as new and undeleted (for imap clients). Daily there would be a rsync of mail storage from primary to secondary, and cleaning incoming messages log on secondary. on primary: 1. Stop qmail-local 2. wait for local deliveries to complete 3. make a snapshot of mail storage volume 4. signal secondary to clean/rotate incoming messages log 5. start qmail-local 6. rsync primary mail storage snapshot to secondary What do You think of that ? Could anyone give me any pointers on how and where patch qmail-queue or qmail-local, or how to make sure steps 1 - 6 get a consistent backup of incomming messages log and mail storage snapshot. Mayby it's posiible to do it in some other simpler way ?
