i've always wondered if the following was possible (w/o virtualization):

load OS from USB flash drive, optical drive, hard drive, or network into the system memory then unmount that device so linux functions ENTIRELY from ram (4 - 8 GB) without a swap file/partition.

if this can in fact be done, could someone point me in the right direction or recommend a distro or give me some terminology to research further?

thanks

You can do this with basically any Linux distribution, though if you are talking about a distribution designed from the ground up for it, I don't know.

This is basically how live CDs work. They load everything into an initrd (Initial RAM Disk), and then run from there. There is no need for a physical hard drive assuming you have enough RAM to make a sizable RAM disk and still have enough memory left over to run your system.

slax. wolvix, and MCNlive all have coppy2ram chete codes avalabel at boot
and fit in 512 or less RAM and if swap is avalabl on the HD OR a USB it's usable

puppy, dsl....

just a side note ----Keep in mind that the hole root file system is in RAM that means /home to so if you start DLing larg files or wat not RAM could fill up and lock the SYS. unless you have a LOT of RAM I'd mount a drive and direct all stuff thare --- and dot forget eney thing saved to the root filesystem will be gone on a reboot

i used several liveCD distros in the past and they all seek the optical drive when loading a program that wasn't opened already in that session.

what im asking about is having ALL I/O operations done in the ram... like loading applications (well i guess they wouldn't have to load since they're already IN the ram at startup).

so if this is possible, how would i go about setting it up?

would i just avoid making a swap partition or somehow map it to the ram?

so a typical scenario would have me booting off a DVD (lets say). all of the OS and any applications i use would be loaded into my 8 GB of ram, leaving 2 or 3 GB for file creation. after everything is loaded into the RAM my optical drive would unmount, leaving me w/ a fully functional OS.

also, DVD could be substituted for other boot methods, PXE network, USB, etc.

does anyone do this in real life? is there a specific distro that facilitates this better than others?

I just gave you 3 of them 4 post's ubuv this take a look and mrclisdue gave 2 more!!!
yes thar livecd's but at the boot prompt you enter coppy2ram and it loads the hole shabang into RAM freeing the cd or DVD drive + thare lightning fast runing frum RAM

You are looking for Puppy Linux. Designed to run entirely from ram. You can set it up the way you like with personal settings, files, and extra programs. Everything is saved back to hard disk, usb, cdr, dvd, whatever you like.

It can be done using several methods, but how about using this little guy if you're looking for the easiest way and the most compatible... http://techreport.com/articles.x/16255 and putting the entire operating system on it

Try Knoppix, it's meant to run from RAM and has a quite feature-loaded cheatsheet for doing all kinds of weird things and running Linux in unusual ways.

Debian