Boot existing ubuntu to ram

[s990we]

I read about booting live cd/usb to ram but i havent found a guide on how to do it with an existing installation.
This must be a good way to increase battery on a laptop?
And it would be faster too?

I was thinking that on boot it loads everything it need to run to ram, then shuts down the harddrive and only use it every x minutes to "sync" files that have been edited and also sync when shutting down/suspending etc.

[v5ar]

here is some very useful info which should get you started
http://forums.debian.net/viewtopic.php?f=16&t=49345

it will surely improve performance, but the part of increasing battery is what i'm not so sure of, it still has to use your disk to write some settings, save your work etc...
you should try puppy lucid linux and see how does that work, that's an example of loading distro into ram, and it saves settings only after you logout, so there is no disk using while you're working,
my point is, better to use distro that's meant to work like that and has everything covered...