For those who use a RAID for your main media storage, I'm curious about to how often you replace it. For example if you were to buy a Promise array today, how long would you keep it in service? I suppose if you just replace the drives as they fail it could theoretically run for many years. If you don't have a drive failure, do you replace all the drives after a certain amount of time anyway or just let it ride?
No point in replacing a drive until it fails, unless you want to waste money and drives.
RAIDs stay in use for as long as they're useful. When you out grow one, sell it on CraigsList or eBay for a few bucks, after getting a larger, faster one and moving your data over.
I know businesses who have had the same RAID running in place for almost a decade. The only reason they'd replace it, is if parts (drive slides, etc) become to scarce, or they get some new XSAN that requires some new hardware the current stuff won't keep up with. But we're talking RAID enclosures with upwards of 16 drives in them.
One oil company here locally still has XRAID rack enclosures, which are ancient. Only reason they will upgrade in the spring, is that they are about out of drives to replace old ones with (drives that small aren't around anymore), and they just replaced an old power supply with the last spare they had. To be honest, I think they're nuts for keeping this one this long. That was just begging for a disaster.
Thanks. Our next system will obviously be Thunderbolt based, and we are trying to figure out what the upgrade cycle will look like. There has been some debate here about whether or not we would need to upgrade the RAID each time we upgrade the edit machine.
One other question: shouldn't a replacement drive be the same model as the one it is replacing? What if that model is no longer available?