that DOES NOT WORK reliably if you are part of a grid! If your regions are connected to a grid it is the asset server that stores your assets permanently. Your own (region) server only has temporary copies aka caches of those items. If you "backup" your server using an image (like Norton Ghost or TrueImage) you'll miss all of the items in the asset server and not rezzed on your region at this moment. If the asset server goes belly up you are screwed as the items in the caches get stale after a short while.
The best advice is given by Lena:
DO FULL OARs of your regions frequently!
DO FULL IARs of your inventory frequently!
Those archives contain the full set of your items and with them you can bring your virtual self to any place allowing the import of said datafiles.