Add more memory? Ubuntu Server 8.04

[CPressland]

Hey guys,

This may sound like a really odd question but i've been pondering on it. Both Windows and Mac see massive improvements with added RAM, but Ubuntu always seams to chug along quite happily regardless of memory space. So I have to ask if adding more really makes a difference?

My server is rather basic, it's running a few PHPBB3 forums with light user access and hosting all my movies to my popcorn hour.

When I do a "free -mt" from the command line it reports I have only "5" (assuming MB) free memory. And the swap file hasnt been touched.

Any reason I should add more memory?

Thanks guys

[PENGUINwithM4A1]

I dont know how good memory allocation is but my server only runs samba webmin and irssi and uses 490/512 mb not touching any swap and i dont notice any performance hit when i start to use the server for things. I would have thought CPU would be the biggest perf upgrade for DB etc.

[CPressland]

I was thinking very much along the same lines. Thankyou for your opinion.

[Vlad]

Free counts memory used in buffers and cache. That's why it says you have so little free. Unused memory is wasted memory, so Linux caches data to improve performance.

For example, one of my servers...

[root@localhost ~]$ free -mt
			 total	   used	   free	 shared	buffers	 cached
Mem:		 32169	  31960		208		  0		200	  15082
-/+ buffers/cache:	  16677	  15491
Swap:		 4094		  0	   4094
Total:	   36263	  31960	   4303

More memory only really helps if what you want to put in memory is bigger than what your memory can currently hold. Throwing gigabytes and gigabytes of RAM at a mysql server who's database is only 100 MB isn't going to improve performance.

If you really want to see how much memory is free (that is, not used by applications) look at the numbers in '-/+ buffers/cache:'.