We have a 20 node setup on 5.0.6 FOSS that we need to migrate to NE 5.0.9.

Are setup includes:

[2] LDAP Servers with 1 virtual IP (managed by heartbeat) - this virtual is what is the registered ldap url (ie: zldap.example.org). The 2nd LDAP server is basically a replica that can be converted to master with heartbeat scripts.

[2] Mail store servers with 1 virtual IP and connected SAN (maintained by heartbeat) - this virtual IP is also the registered server name (ie: zwebmail.example.org). The 2nd mailstore is offline and used in case of hardware emergency from the primary.

[2] MTA Relay Servers each having their own Zimbra server identity, and a virtual IP for DNS names to point to (ie: zsmtp.example.org)

[14] MTA MX Servers each registered in Zimbra as zMX[01-14].example.org)

The Mail Store Primary, MTA Relays, and MTA MX Servers, all use a local LDAP Replica.

Our Goal (Simply Put) is to run 5.0.9 NE.

I see two different paths we could take

Option 1:
Upgrade 5.0.6 FOSS to 5.0.6 NE, then upgrade 5.0.6 NE to 5.0.9 NE

Option 2:
Upgrade 5.0.6 FOSS to 5.0.9 FOSS, then Upgrade to 5.0.9 NE

The sequence of upgrades is basically DB(LDAP), Mail-Store, MTA's

Thanks again!