[rotuts]

I have a brand new 5 bay Mobius external drive box that im using via 3.0 on my iMac

in its set-up instructions is it recommends enterprise or NAD drives. drives such as seagate green, blue, black, Barracuda are not recommended and may inhibit performance and limit technical support

I have one seagate 'NAD' and two seagate 'desktop' drives

what's the difference between 'NAD' and 'desktop' Im using the box as a 'plain' HD box, not RAID

under 'clear RAID' the company also says JBOD provides no performance increase or redundancy

what do they mean by this ?

many thanks

[Mike Wuerthele]

JBOD isn't a RAID, JBOD is a "Bunch Of Drives" with no redundancy, striping, or mirroring.

[rotuts]

"" JBOD isn't a RAID, JBOD is a "Bunch Of Drives" with no redundancy, striping, or mirroring. ""

thanks Id guessed that. what about 'NAD' vs 'desktop' the company's concern for drives that are not NAD or enterprise

might have someting to do with RAID usage, and the drives they do not recommend for RAID for these reasons

they don't mention recomended drives for 'Bunch of Drives' which is what Im using the box for.

[mooblie]

I believe you're thinking of the term "NAS" (Network Attached Storage), not NAD. Of course, you can refer to this as you wish, but "NAS" will find lots more relevant Google hits.

"WD Red" drives are specifically designed for NAS use - i.e. powered on all the time, longer warranty, appropriate compromise between power consumption, speed, reliability, price, etc. etc.

WD will honour a warranty for a Red drive that's been powered on 24/7. They can tell, of course - which they might not honour for their other "non-NAS" drives. FWIW: I use a set of four WD Red 2TB drives in an HP N40L Microserver (with NAS4Free software).
http://www.nas4free.org/
Works brilliantly.

[P]

The main difference between NAS drive (such as WD Red) and a regular desktop drive is how they handle errors. A normal desktop drive that encounters an error will try and try again to attempt the operation anyway. During this time, it is unresponsive. A NAS or RAID controller might give up and read this as a completely broken drive, mark it as bad and use the redundancy features to save your data. Unnecessary, if it only has a bad sector or so. NAS or RAID focused drives let the controller decide how long they should retry an operation and let the controller decide how to handle it - if it is RAID 1, they can fetch the read data from the other mirror, for instance - so the controller never marks a drive bad incorrectly.

There are a couple of other things. mooblie mentions one of them - the extended warranty. The others are the increased vibration tolerance - if in a small chassis with nothing but drives, you might need that - and special power management schemes where the drive will reduce speed but never actually stop and park its heads, as that would also cause it to be marked as bad by the controller.

[rotuts]

thank you all !