First of all, suck it Neil Conner.  I’m about to disagree with Ed (again) and there is nothing you and your fish eating friends can do about it.

Gotten away with it? I’m not stealing bread from the supermarket, I’ve made a calculated decision. I run 18 MD1000s in this configuration globally and I have yet to lose an array. The added capacity and speed benefit of a 15 disk raid array (no hot spare) is plenty worth the risk of the array going down.  Further, this risk is mitigated with properly configured Dell OpenManage which alerts me immediately if a disk fails so I can have it replaced.

Sure, I may eventually lose an array, but this is backup data. It’s importance to most businesses is somewhere between Dev and QA, and if I were (worst case scenario) to lose a Raid5 and 10TB of backup data, then I’d inform the appropriate application groups and move on. It’s not like most of the data isn’t probably ok (backup not needed) or on tape (array not needed) or has incremental available (also on tape.) This isn’t a production database or file server, it’s backups, IMO, Ed’s “every bit counts” attitude is completely out of step with the real world.

-Jonathan

PS: I do agree with Ed about 1TB disks, but in my case because of the poor performance not the raid implications. 15 x 500GB SATA in a Raid-5 is the backbone of my  operation.