backup a memory based db

[CHarles Pareto]

I would like to use a memory based db for my project. My db is only a couple of MB's in size so I think it would be perfect, but the data in a memory based db erases if the db is shut down. So I thinking, there are very few writes to this data base every day (like 5-10) so what if I do a hard backup of the whole bd every time a write occurs? This way I save the database in a hard copy in case the the power goes out or someone unplugs the server. And when the power gets restored I have a hard copy that can be loaded right back into the db.
Is this a good idea?