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Heck, you could even get storage appliance (firewire or?) and use a cron job to copy the files to the drive at night. Then there's no messing around. Write the whole drive and all the files associated with the DB to the drive. If the production drive crashes - you've got a ready made spare.
I need to experiment with hotcopy a bit, but I think copying the files themselves is the best option. The indexes would thus already be built.