Well, working with
HostNuke for the last year (a year as of this friday) I've learned a few things having to do with dedicated servers (and the Ensim enviroment) that I want to share with everyone (as well as get some input on what others do on their servers)...
TimeA fun thing about some systems is time drift, the offset from the time on the server to the time in the real world... Leaving a server alone for a few months and just updating the time I've had them off by as much as an hour... To fix this we simply setup a cron task to update to time.gov every night (midnight, yey!)... Needless to say, our time drift is bairley off by a minute every nightly update.
ZendI've seen a shared server (300+ sites) be extremely slow at times, so slow that it'll take 45 seconds for one page to load... Installing Zend Optimizer made the example site load in 3 seconds vs the original 45 second wait...
MySQL TweaksWe updated the flush hosts limit to 100,000, mainly because we didn't care that 300 requests where sent per second as when it hit the limit it'd shut down MySQL and we'd have 900 complaints that sites wheren't opening and users getting a "Please flush hosts" message. Originally this was upped to 100 (from the default of 10) then to 1000 (as the 100 limit actually (rarely) got hit). It's now resting at 100,000 due to not wanting to have to "play" with it any further (it's stable enough to guarentee 99% uptime).