Moving wpmu to another server and upgrade

Hi Guys,
I've my wpmu network with wordpress 2.9 on a server.(travellertribe.com)
Now I would like to move it in another server and, with this occasion, upgrade to wp 3.1 and istall buddypress.

Since I've seen several differences between wp 2.9 and 3 , including the "mu-plugin folder" in wp-content, my questions is:

1) it is a wise chooise to just upgrade my current version and than move to the new server?
I means, does this way can somehow hurt the DB or folder structure and penalize me with bugs, problem or SEO issues?

2) Does there is a way to easly backup all the installation and move it in another server?

EXTRA QUESTION:
I've an english installation in the root an in a it. subdomain an installation for italian content.
Now I would like to merge this, and other languare in the nexts months, with the MultiDomain Plugin.
There is a way to import all the blogs/sites on it. subdomain in the plug-in so user can have access both in english and other language version with the same account?

Thanks!

  • Barry

    I, personally would do the following:

    1. Get new server
    2. Back up current site and transfer everything to the new server, keeping the same version of WP.
    3. change your local machines host file to direct the sites URL to the new servers ip address, so you can access the site at it's current name whilst everyone else can access the old site still.
    4. Upgrade WP on new server and test for bugs, etc....
    5. Change dns to point domain to new server
    6. Remove your hosts file change.

    You may lose a little bit of content during the 2 - 5 steps, so may have to do another wp-content / db transfer at point 5' or put a warning on the site that you are moving servers so some content may be lost in the transfer.