I learned about RAID 1+0 after this. I thought RAID 5 was better but I never heard of 1+0 until this outage. So did more than one disk fail? I've operated 3-disk SQL databases and had one fail. Just swapped in a new drive and it ran like a champ with no down time.
Doesn't seem that complicated but who knows maybe there's something different.
This forum is pretty old, imagine if they didn't replace new disk every few months, the wear and tear is enough to degrade/corrupt a disk. Two disk failing at the same time is pretty low but possible as they have been running at the same period of time and most likely having same amount of wear and tear. Raid 5 isn't recommend for large disk, bitcointalk probably function on large hard drives due to the amount of post and other things.