Tips for Increasing Server Availability?

uptime asks: "I've got a friend that needs some help with his web server availability. On two separate occasions, his server has had a problem that caused it to be unavailable for a period of time. One was early on and was probably preventable, but this latest one was due to two drives failing simultaneously in a RAID5 array. As a web business moves from a small site to a fairly busy one, availability and reliability becomes not only more important, but more difficult to accomplish it seems. Hardware gets bigger, services get more expensive, and options seem to multiply. Where could one find material on recommended strategies for increasing server availability? Anything related to equipment, configurations, software, or techniques would be appreciated."

Where's the link?

[azuroff]

Just post a link to this server of his - we'll gladly stress-test it for him at no charge. :)

Not a bad idea...

[Ingolfke]

I think sysadmins would respond very nicely to tips for increasing server availability. Let's say average tip is about 15%, and for simplicities sake we'll say that every hour of downtime costs about $10,000. Baseline service should be set either by an SLA or a measured baseline. For this we'll say 99% uptime per month. That allows for 7.2 hours of uncscheduled downtime in a month. So if the server is up for 100% of that time, then you'd want to tip your sysadmin about $10,800 per server (assuming the #s stay the same) for a month of great work.