I tried to migrate my old system from 4.5.4 GA on CentOS 4.4 32 bits to 4.5.7 GA RHEL 5(64 bits) on cluster. After consulted with professonal ppls, here are the suggestions I have.
Because 4.5.4 GA doesn't support RHEL 5(64 bits), I can't restore from 4.5.4 GA CentOs(32 bits) full backup to 4.5.4 GA on RHEL 5(64 bits) by following the wiki Network Edition: Moving from 32-bit to 64-bit Server.(not - ZimbraWiki recommanded) After that, I can just perform a 4.5.7 GA upgrade on RHEL 5(64 bits) then. But seems it's a not recommanded way to do.
The safe way I can perform is "IMAPSYNC" which is I am doing right now.
My questions are
1. Is the method provided above(not imapsync) really not working? I should go with imapsync only?
2. Base on current release Zimbra have, there is no cluster option on RHEL 5. What kind of fail-over/cluster option I can use here? Can I follow someone's post by implemeting heartbeat?