Actually, Hard Disks are reliably unreliable!
I agree with Gene Cash, HDs regularly die without warning. I've many boat anchors around me--boxes of dead HDs, mainly Seagate but with a sprinkling of WD and Samsung thrown for good measure as I've already said in an earlier post a week or so ago. These masses of dead drives have caused us considerable angst not to mention hundreds of hours rescuing data despite having a reasonable backup regime. (We've even had new HDs fail when in the process of storing rescued data from failed drives.)
Simply, the facts are that these hard disk manufacturers are making product that is reliably unreliable and they deserve to go broke unless HD reliability is urgently and dramatically improved! They're making drives at the limit of technology and they're doing so whilst cost-cutting in the extreme. It's pointless having $0.50/GB cost if the data frequently vanishes off the platter into the aether without warning.
Anyone who knows the vaguest about the operation of HDs knows that these manufacturers are already pushing the HD design envelope into unreliability. Raw data coming off HDs is already below the noise and has been so for quite some time, and if it weren't for very efficient data separators and error correction these HDs wouldn't have a hope in Hades of ever working let alone make it out of the factory. Essentially, the data density on large terabyte HDs is so high that what is recorded is hardly recorded at all.
One of the consequences is that even when HDs are used as non-operating backups they'll often fail in storage. It's a risky business keeping a drive containing a million or so files stored for a year or two, it's far from a certainty that you'll get the data back after this time. This means that users have to employ more redundancy by using more B/U drives--the drive price war is really a false economy, users end up eventually paying the equivalent of much better manufactured drives but with a lot less convenience.
If drive manufacturers are to wean many of us off SSDs back to HDs then they'd better stop the bullshit about MTBFs of millions of hours--which most know is utter crap--and genuinely make their drives more reliable.
Here's a few suggestions:
1. Make the essentially useless S.M.A.R.T. reporting system actually work by being effective and meaningful.
2. Build beepers and indicators into HDs that scream out audible warnings and flashing lights at the first sign of trouble, these failure indicators would work independently of any computer--just power-on would be enough.
3. Build in redundancy--a complete and independent second head assembly with its own separate head amp electronics and such (in normal operation this could be used to increase drive throughput).
4. Provide a rescue/data recovery mode--drive goes into slow speed mode where heads are lowered very close to or onto the surface for a once-only recovery pass.
5. Provide standardised outputs between the HDs PWA/electronics and the drive chamber electronics--when the drive electronics fails then it's easily replaced or the chamber can be easily coupled to external recovery electronics.
6. Stop the ridiculous secrecy surrounding the operation of HDs which stops people rescuing their data from failed drives. Tell users about the internal drive protocols and how the manufacturing test jig connections work etc.
Of course, such notions are both obvious and revolutionary--so revolutionary in fact that we'd be back to the way electronic maintenance was done prior to say 1980 when maintenance handbooks, revision sheets and circuit diagrams were commonplace and openly available.
However, don't hold your breath. In this age of secrecy, hidden IP info and such, manufacturers would, it seems, prefer to go broke than provide the customers with what they actually want: i.e. reasonable protection that their valuable data won't vanish off into the never-never.