WordPress MU

how can change the domain of MU at later date?

Run a search & replace on the database.

really is it that involved? why cant i just change the settings in the admin area?

i need to change

mydomain.com/myfolder/

to

mydomain.com/mynewfolder/

or just

mydomain.com (using virtual host)

Because it is stored in a great many places.

You have to be careful doing a blanket search & replace. If the new URL changes the file path to uploaded files, it will break much of the metadata associated with uploads in the database. File upload information is stored a serialized array (or object, can't remember), which include a length as part of their serialization. If you change the length of the string, the array won't unserialize correctly and you'll lose the metadata.

You could work around this by setting up a symbolic link between the new and old folders, or by manually fixing the length parameter of the serialized arrays. The latter is what I have done in some cases, but is generally pretty tricky.

Or, if you don't need that data, don't worry about it.

"If the new URL changes the file path to uploaded files, it will break much of the metadata associated with uploads in the database."

Yep, but you could also change thsoe occurrences as well.

Bigger SQL statement, but do-able.