This is simply a warning for others. I picked up a 3ware 9650SE-8ML RAID card two days ago, and 4 drives to go with it. I figured I'd go RAID-6, 2 drives worth of date and 2 drives worth of parity..... wrong! Apparently 3ware's algorithm requires a minium of 5 drives. Wowsers. RAID-6 should be a minimum of 4. Now in fairness, their USERGUIDE for the card states the minimum in the section on adding raid arrays, but their datasheet, nor their references RAID-6 tech brief document say this. In fact, their own RAID-6 tech brief says RAID-6's minimum requirement is 4 disks. Oh well.
Beware.
I think 4 and 5 HDD still can use raid 5, no big risk for 2 HDD degradation, when use 8 or more then only raid 6.
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