You need to know how to setup DRBD and HeartBeat, that I can not cover in this thread.
we have two boxes, Node1 and Node2, and a Virtual IP by heartbeat
install Zimbra on both disks
then DRBD the /opt partition, zimbra should be working on either node1 or node2 depending on which one is primary or secondary
Setup heartbeat to monitor the VIP and bring up zimbra in case of failover
i.e. /etc/ha.d/haresources/ on the first line type
This can also be done by hand, you don't need to have heartbeat.
node1 drbddisk Filesystem::/dev/drbd0::/opt::ext3 x.x.x.x(your VIP ip address) zimbra
/opt will switch over between the two nodes
As far as one-to-one Nat, point your public ip address to the vip address
- I recommend identical boxes for both nodes to make things easier
- Upgrading Zimbra is simple, just run the upgrade on the Primary node (active). I've performed an upgrade from 4.5.7 to 5.0.5 with no problems thanks to the amazing upgrade process Zimbra has.
YOU NEED TO STUDY DRBD or else you risk hosing your /opt partition.
1 stop ha on node2
2 stop drbd on node2 ->now shutdown node2
3 stop ha on node1
4 stop drbd on node1 ->now shutdown/restart node1
-> turn on node1
5 start drbd on node1 (can't find the other, bypass, say "yes")
6 start ha on node1 (auto)
-> turn on node2
7 start drbd on node2 (auto)
8 start ha on node2 (auto)
Also look into the SPLIT BRAIN PROBLEMS that DRBD may encounter, thats when both nodes don't know who will take over the main partition. Please practice messing around with DRBD before you put a production system online running a DRBD parition.
I hope this helps. Sorry I can not be any more detailed at the moment.