Is it possible to clear ram in linux with out rebooting the server?

Why do you think you need to do this?
Do you want to end all processes except those which are vital to the kernel continuing to run?

man ps
man kill

clear the ram? if you're not up on the memory model of linux, it is designed to sotre as much previously used data in the ram as possible, in order to make programs restart faster. the space is always efficently reclaimed if it is needed for new processes

ok well basicly I am running out of ram and its going into the swap do I need to add more ram?

Not unless it's using all the swap. My system usually uses a few megs of swap despite half the ram not being used. It's just doing it's thing to keep the most used processes going as fast and efficiently as possible.

ok

" Yes Linux uses your ram. What?-Did you want it just sitting there unused so you could brag?"

Was that in your sig before you answered this thread? What a coinkydink.

ok goofy........ I run game servers I have 3GB of Registered DDR in my server right now I don't want to have to add another GB so I am trying to figure out a alway to clear up my ram

Nah bulliver, I changed it after 3 people posted about the linux way within a few hours of each other. I moved all my links to the LQ bookmark listing too.

eyexer0, have you read about tweaking your kernel to recognise more than about 512megs ram? Or any other info about ram-rich installs?

nope I just thought you put the ram in and go? should I be doing something to my kernels?

From checking the Similar Thread Kernel not reading all available RAM listed below, I see there is a highmem kernel option, as well as arguements which can be passed to the kernel via your bootloader (Lilo).
think you'll have to browse online for info on others with similar servers. Dont forget to run lilo after changing /etc/lilo.conf for the changes to take effect.

I run grub :/

my system recognizes 1024 megs just fine without kernel tweaks.

Reconizing the ram and using it efficiently is too different things, Once you are above 1 gig of ram it is good to do a kernel recompile to configure your server to make the best use of its resources.

A really bad example but I will give it anyway, I had someone bring in a windows 98 machine with 640 megs of ram, it reconized it but it was running worse than normal, by microsoft a windown 9x machine can only reconize 512 megs of ram, but it starts degrading in performance after 256 megs, so there is a case of an os reconizing alot of ram but not using it right.

Linux could be the same with 3 gig's of ram, fortunatly it can be easly configured to use all that ram where the windows machine in my example above could not :-)