We need to accomplish the following within the next 6 months and trying to plan the best approach to minimize downtime.

Currently running ZCS Network 5.0.21 under RHEL4 64bit. We need to:

* Replace hardware
* Upgrade OS to RHEL5 64bit
* Upgrade to ZCS Network 6x

There's an actual planned SAN upgrade, but that's a different ball game!

Currently, /opt/zimbra is on a SAN via fiber. I'd like to avoid doing an actual OS in-place upgrade, and definitely not on the new box.

What would be the recommended path? In our case, we don't need to do an rsync as the LUNs will be remounted on the new box.

Of course and depending on down time needed, I would be able to do multiple outages.

Also, we have a full dev environment to be able to test.