Hi. i think this question is pretty simple to answer, but i just bought my dedicated server and im a noob. here it goes : I bought a Celeron 2.0 with 1Gb ram. I have 2 websites running there (the biggest one with 4k uniques and 15k pageviews day), and when i go to statics i see that i still have about 800mb of free ram. But, if after 2 days of being on (without restarting), my servers shows about 20mb of free ram. Is this bad? is the website getting slower because of this? How often should i restart it? Thanks a lot
The problem, IMO, is your server's processor. Everything else seems to be fine. If your site is powered by PHP/MySQL, it's a processor-resource hog. Do consider contacting your host for an upgrade to a Pentium 4 or AMD Athlon processor. You'll see much improvement, trust me; it shouldn't cost too much extra for the upgrade.
it is not necessarily bad. it depends on how you are measuring and interpreting the measurement. as long as your site is fast and responsive, there is nothing to worry about. after all, it makes no difference to your users what is happening behind the scenes as long as they get their pages.