hi.

On Feb 28, 2011, at 1:27 PM, Anthony Carrico wrote:

> Nobody recommended any software to exercise a drive to try to catch
> infant mortality before putting the drives into service.  

I use bonnie++ to test disk arrays. http://www.coker.com.au/bonnie++/

> Jonathan: It is true that Western Digital has disabled the ERC parameter
> on these drives (for marketing reasons, I suppose).

Not sure what you mean...

Enterprise Disks differ from commodity disks in more than merely the fact that 
they offer features on vibration, sensors, etc. The point I was making in my 
post is simply this:

Enterprise Disks have RAID compatible firmware.

Commodity Disks (recent makes) do not have RAID compatible firmware.

The consequence is that even in a software RAID the disk might fall out of the 
RAID array because Commodity Disks enter "Deep [error] Recovery Cycle" or ERC 
as you note. The RAID capable disks have a Time Limited Error Recovery (TLER) 
to prevent this from happening. Different uses, different firmware. Again, see: 
http://wdc.custhelp.com/app/answers/detail/a_id/1397/p/227%2C294/

So, as I read it, the basic story is this: 

Buy the best disk available for your data and storage context. If you plan to 
RAID the disk, make sure that the specific disk's firmware is compatible with 
the RAID controller (software/hardware/operating system). If not, then you risk 
losing the disk, array, or data. Disks made for RAID are *made for RAID* these 
days. 

I'm sure one of you enterprising geeks could figure out how to hack the disk's 
firmware, something like http://flashrom.org/Supported_hardware comes to 
mind... :P But, I'm too conservative with data, and wouldn't be comfortable 
risking that kind of a maneuver. 

To speak to Sam's post, *I* am conservative with how I 
treat/handle/store/process *my* data. I don't want to lose it. To that end, I 
feel that a strong warning to those unaware of these potentially data killing 
issues, is better than no warning, or just buyer-beware. In my unvarnished 
opinion, data storage should not have traps set for consumers, and this is one 
such trap. I was disappointed to learn of the difference, so I felt obligated 
to warn all of you.

While it is possible to use a cheap disk in a RAID, it is NOT something I plan 
to do to store data I (or another entity) truly cares about--- and that's what 
Sam said: If you know the risks, and want to take them anyway... not my problem.

> This isn't my plan, but consider this:
> 
>  $260*2 RE4 = $520 -> two disk raid0
> 
>  vs.
> 
>  $79*7 WD20EARS=$553 -> four disk raid0 + two hot spares + one cold spare
> 
> The math for the latter really kicks the former.  Inexpensive means
> something in raid.

Yes, though I'd suggest a modern correction: inexpensive used to mean something 
in RAID. Modern RAID is used for Enterprise, and prices are adjusted 
accordingly. I'm not saying I agree with this state of things, but it is the 
current state, so far as I know. :P

> BTW,  the RE4 has just as many failure reviews on NewEgg as all the
> other drives, maybe more.  I suspect that shipping is the problem.  I've
> got four drives from two shipments, so I can put two drives from
> different shipments into my server which should help some.  It would
> have been even better to order from different vendors.  I put some data
> in my original post about the shipping containers.

Yes. Until very recently, NewEgg didn't know how to ship HDDs. Customers had to 
TEACH them. My disks were shipped in a bulk package--- 6-12 disks per pack, and 
it was well packaged. Basically, NewEgg got lazy, wasted several hundred disks, 
and has the reviews (and black-eyes) to show it. I still buy stuff from NewEgg 
however, though I choose to ship disks the *expensive, we don't throw your 
stuff around* way with FedEx.

Good luck.

have a day.yad
jdpf

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