Compelling Alternatives to RAID Setups?

jabbadabbadoo asks: "Our software shop has about 30 Linux servers and 15 NT servers running enterprise applications for our customers. Since we have service level agreements with most of them, uptime is crucial. One of the things we've done is to use RAID setups extensively, using products from well renowned disk- and controller vendors. However, we have discovered the paradox that introducing RAID controllers actually reduces overall uptime! Not only does more 'steel' increase the probability of failure, but what fails first is usually the RAID controllers. What is your experience? Have we been having bad luck?" "A related problem, especially on Linux, is that setting up RAIDs is actually a quite costly process. There seems to be endless problems with library versions, and upgrading existing servers simply takes too many hours. To keep the customers happy, we routinely have to create a 'shadow' server while upgrading which in turn means we, at some point, have to synchronize data to the new server, which in turns means a bit of a downtime. Ouch. Does anyone have a good solution to these problems? Of course, cost is a major issue, but so is uptime (which also means cost if we don't provide the uptime dictated in the SLA). What setup gives the best cost/uptime ratio? Thank for any thoughts!"