[nylug-talk] Paper IT certs and disk drive fabrication differences -- WAS: Slim home server

[Bryan J. Smith]

Chris Knadle wrote:  
> I'm having trouble with the above paragraph; I just don't buy the idea
> that hard disk manufacturers can drop warranty support based on the number
> of hours per day that they are used.

With Joe consumer?  Depends on the federal or state/local consumer laws.
IBM tried to limit usage to 14 hours/day max on its consumer drives
after the infamous, 5x15GB platter Deskstar.  They sold their division
to HGST shortly afterwards.

If you're sending dozens of drives back, you can be sure that the
manufacturer will take note.

But with Dell, HP, IBM, the manufacturer can _refuse_ to replace drives
when their volume contract specifies, in writing, what they are and are
not allowed to ship for what purpose.  That's where the sampling
differences first started.

You can't sell a sizable product line without running into this.  In
fact, when you "resell" the product, your "warranty" enters a whole new
level of complication.  ;)

Chris Knadle wrote: 
> Let's cut to the chase and examine a specific example...

We can't do "examples" because you keep having a debate with something
you think I said, but I did not.

Also remember that is the "retail" unit.  The OEM units are very
different, and the terms may be with the reseller, not the manufacturer.
People forget that.  ;)

> Nowhere in the documentation listed are there any specified limitations
> on the number of hours per day that the disk should be used.  Not the
> specifications, not the datasheet, not the warranty.  And it's a 5-year
> warranty on a commodity disk.

400,000 hours MTBF based on 50,000 restarts and 8 hours/day usage given
no adverse, off-line or on-line events.  ;)

> The fact that it's meant to be a "desktop hard disk" doesn't mean anything,
> at least not to me, because some people never turn their desktop computers
> off, and I think that's to be expected.

Yes, but their drives are not spindling 24x7.  ;)

> I think I understand that your point is that "enterprise" drives...

Again, I ask you, "which enterprise" do you mean?

- Enterprise fabrication?
- Or commodity fabrication of samples tested to higher standards?

> are meant for continuous use and that "commodity" drives are not,
> but I personally can't bring myself to agree with that conclusion.

In all honesty, at this point, I not only do _not_ care, but I can_not_
care.  Why?  Because you are having a debate with what _you_ think I
said, not what I actually said and meant!  You are also not
differentiating between multiple classifications of drives, which only
adds to the problem.

It's all about sampling, statistics and the rate of failures as a
result.  The manufacturer knows drives fail, so it has come up with a
set of QA that it samples -- again, only samples -- lots for to see what
type of average quality is resulting.  From that, they will gear their
usage towards different environments.

> My gut says no, my "engineering intuition" says no,

My gut "reading comprehension" says, stop reading into what I'm saying.
Don't assume what I said.  Read what I said, step back, and try to
realize what I'm saying.  It's not black/white.

> and from what I can see the online documentation doesn't support that
> conclusion either.

You're reading consumer documentation on a retail product.  And you're
glossing over many details without recognizing them.  That includes
"reselling" a product.

> If they're only supposed to be used 8 to 14 hours per day, that has to
> be in the documentation, or else I believe any court is unlikely to rule
> in the manufacturer's favor should a legal case be brought.

If you "resell" a product, or use it in a way that does not fit the
commercial code, then all bets are off on warranty.  E.g., you take the
product out of its retail packaging and resell it.  That can be a
problem when you do it for hundreds of units.

The manufacturers don't care about 1-off consumer usage.  What they care
about is people reselling hundreds of them.  Again, the commercial codes
gets rather interesting on this.

> The only thing I can see a manufacturer doing is looking at the purchase 
> date of the drive, and whether the drive had an event happen to it that
> isn't covered by the warranty; drop > X number of G's, opening the case,
> lost password, etc...  there's a list of those stated exceptions in the
> warranty.

A warranty that applies to a particular means of sale for a particular
usage by an end-user.  When you start reselling, and you do hundreds,
then you're getting into aspects where your warranty can change.
Whitebox vendors have to be very careful, and I've seen several larger
ones run into issues.

IN A NUTSHELL:  

  If you're selling hundreds of units as an OEM, don't play stupid.  ;)

> Wow, you mean you've actually replaced the CPU microcode?

Intel offers a volatile storage area on their CPU for years.  For Linux,
they offer a loader.  Otherwise, you typically have to wait on a BIOS
update.


-- 
Bryan J  Smith              Professional, Technical Annoyance
mailto:b.j.smith at ieee.org  http://www.linkedin.com/in/bjsmith
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