I’ve been having memory issues on my server/cruncher box : available RAM seems to disappear. At first I thought it might be the well-known Firefox memory leaks, so I did a little (unconscious) experiment. I rebooted yesterday and never fired up FF. Today, I notice:
bobo% free -m total used free shared buffers cached Mem: 3943 3673 270 0 161 3253 -/+ buffers/cache: 257 3686 Swap: 6000 110 5889
Something appears to be caching to buggery. It turns out to be the kernel. The trick here is to interpret the second line, which tells you what programs “see” when asking for memory. In this case, it’s 3686M free, so all is well. A little scary there for a second…
I shall have to be a little more sanguine next time.
 dual amd64, 4G RAM, Ubuntu Dapper clean install.