Migrating 32-bit 64-bit and new version.

[msopacua]

Hi,

I'm tasked with an upgrade of an inherited zimbra installation:
Release 5.0.6_GA_2313.UBUNTU6 UBUNTU6 FOSS edition

As one can see, neither the OS nor Zimbra has been kept up to date, so I'm looking for some advice on the preferred order of the following tasks:

• Upgrade OS to ubuntu 8, 64-bit (it is now 32-bit)
• Upgrade Zimbra to 6.0.4
  
  

Since I'm not intimate with zimbra just yet, I'd like the end result to have the same settings and data. No changes in DNS etc will be made. The upgrade will be done on the same machine, but I have an Ubuntu 8 64bit machine here for testing.
If at all possible, I'd like to simulate the zimbra migration on the test machine with a back up of the live data.

Thanks for any advice.