[Discuss] Striping is bad

[alex at pennace.org (Alex Pennace)]

On Sat, Feb 18, 2012 at 09:55:52AM -0500, markw at mohawksoft.com wrote:
> Most of us have been in the business for some time now and know, wuite
> well, the does and don'ts of technology. As we all know, sometimes you do
> things that you think will "be ok." "It won't happen to me." etc. I set up
> the system with striping (RAID0) with no redundancy.
> 
> Well, I got burned. I have a DLink DNS-321 NAS box. I've had it for almost
> two years. When I bought it, I bought two 1TB Hitachi drives. On
> valentines day, drive 1 dies a hard death. No bad sectors, no partial data
> loss. The drive would not even spin up.
> 
> I took the electronics board from the good drive and tried it on the bad
> drive. The motor spun up, but the disk arms would not move (no audible
> motion like the good drive).
> 
> So, I lost some data. Most of it is scattered across 3 or 4 laptops and my
> desktop, but some if it is lost forever.
> 
> So, two lessons learned: (1) when you know better, listen to yourself. (2)
> don't buy Hitachi hard disks.

We recently had something similar happen, luckily the logic board swap
was successful. 

At the time we created this array, we went with RAID 0 because the
data that was supposed to be stored on there was temporary in nature,
or there was another copy of it somewhere, a fact we made clear to the
users. We also needed 1 TB of storage, and only had 500 GB drives
available for this purpose.

Or so we thought. The users acknowledged being told that there was no
guarantee, nevertheless they were quite interested in the fate of this
data.

So, we recovered the data, and rebuilt the array with two 1 TB drives
in RAID 1. For bonus points, I moved the logic boards back and sent
the dead drive in for replacement.

So, lesson 3: Even if you think you got your butt covered, you don't.