I would like to use the low cost Caviar Green (Western Digital WD20EADS 2TB or WD10EADS 1TB) hard drives in a raid hardware for a not mission critical purpose: is anyone aware about problems due to the rotation scaling (5400 - 7200) typical for these hard drives?
thank you
The only problem we've had with them at work (we don't have many, but a few) is that they're pretty darned slow. If you need a lot of storage, but not a lot of IOPS, then they seem to be a pretty decent way to go.
I've been running the 4x WD10EADS on 3Ware 9650se SATAII RAID without any issues. While I'm aware of the scaling issue, I don't think it's a problem for hardware RAID controllers in general.
I've ran the greenpower drives in a RAID configuration for a couple of years now in three different setups: connected to motherboard for software RAID, connected to a RAID card, inside of a Drobo. Performance was always the best on the RAID card because it never let the drives go to sleep, so there wasn't a delay while the drives woke up. However, because of this it always meant that power savings came only from lower rotational speeds and not their ability to sleep. Directly to the motherboard worked pretty well, but the spin up times were annoying. I was using the drives to record hdtv and I'd tend to lose the first few seconds while the drives woke up. Finally, I got a Drobo and put the drives in there. Spin up times are really annoying now, but I've stopped using them for primary storage. I just migrate data there as long term storage.
So, no problems with rotational speeds. It seemed that my rather cheap (~$200) RAID card handled it with no problem. But just be aware that you're not going to get the same power savings you'd get on a desktop machine if you've get them connected to a dedicated card.