>>>>> "Maarten" == Maarten <maarten@xxxxxxxxxxxx> writes: >> You could use jbod mode (or create single-disk "raid arrays") with >> Areca or 3ware controllers and use software raid on top of that. Maarten> True, but then that would kind of defeat the whole purpose of Maarten> the fairly expensive card. In that case a better investment Maarten> might be a sort of servergrade motherboard which has 6 good Maarten> onboard controllers and at least two separate PCI buses for Maarten> the add-on cards. (For the price of one 12 port Areca you can Maarten> already buy a bare bones low-range server...). Maarten> The main selling point of most hardware raid cards is that Maarten> they seem to be doing a much better job predicting failure of Maarten> a drive than software raid can. I don't know how they do Maarten> that, but a fact is I've never even heard of a two-disk Maarten> failure with hardware raid. Which of course doesn't say it Maarten> cannot happen, but it does seem to be a lot less likely Maarten> somehow. Hah! I'll trump that. In a previous job we had a bunch of Netapp Filers. Nice boxes, really nice and reliable. We had a two disk failure in one volume, so they do happen. Managed to get it back by swapping the disk driver controller board between the really failed drive and the second failed drive. Took quite a few hours of mucking about, but it was certainly better than losing the data and doing large restores. Nowdays Netapp has their double parity Raid6 like setup for data, since with 1Tb disks,a second failure isn't all that unlikely. Pretty soon I suspect disk^Wstorage will be cheap enough that we'll just mirror and snapshot and try NOT to write to offline media if at all possible. Except for data which hasn't been accessed recently. HSM anyone? John -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
