SuSE 10.3 Memory usage issue

I’m not sure if this is the right forum for this. I have OpenSuSE 10.3 64-bit on an AMD 5200+ with 4Gigs RAM. I notice that all the RAM is used all the time, even with almost no applications, it is 98% full or more…and the swap file has almost nothing (even though I have confirmed it is turned on) Is this normal? It seems the system would be sluggish with no free RAM to start new applications or for copy operations. Copying/moving seems slower than it should. Moving large items (like an ISO) to the trash also seems slow.

this is normal under Linux. It buffers and caches as much RAM as possible for faster operations… besides, free RAM is useless. I have currently half of my RAM used and the other half buffered. You shouldn’t worry about Linux memory management, it’s superior to the Windows memory management

With Linux free RAM is considered wasted RAM. Anything that has to be run or loaded from the hard drive is going to be very slow. If you have lots of RAM why not load functions and such directly into RAM and run it from there?

This is a very simplified view of memory mapping. Basically, your memory is all mapped out for use by the operating system for more efficient use of that memory.

For more in-depth reading:

Explore the Linux memory model

Now, to understand how much “free” RAM you have, look at the output of the ‘free’ command:

total used free shared buffers cached
Mem: 3094204 898952 2195252 0 49012 484528
-/+ buffers/cache: 365412 2728792
Swap: 2104472 0 2104472

It appears that all my 3GB of RAM are in use. Actually all my RAM is ‘mapped’ not used. You see the line “buffers/cache”? That shows that the OS is actually using 365412k of RAM leaving 2728792K free. This number represents the actual amount of RAM available to the system. What Windows users refer to as “free RAM”.

I can understand that, but what then is the purpose of the swap file, and what might be the explanation for the long times moving objects to trash? (and why is there no “delete” for us who know what we are deleting?)

the purpose of the swap partition is the same as the page file on Windows. If you somehow manage to run out of available RAM, the swap file will be used… and there is a Delete, at least in KDE there is

open up konqueror, go to Settings -> Configure Konqueror -> Behavior and check the box that says: “Show ‘delete’ context menu entries which bypass the trashcan”

after that, right-click on something and choose Delete

Thanks for your help.

Except that Windows, if I’m not mistaken, will dynamically use the page file to cache certain pieces of code and data, even though there is physical memory available.

True, which is why Linux is much more efficient with managing RAM.