Re: [gentoo-user] Testing a used hard drive to make SURE it is good.

[Dale]

antlists wrote:
> On 16/06/2020 12:26, Dale wrote:
>> I've also read about the resilvering problems too.  I think LVM
>> snapshots and something about BTFS(sp?) has problems.  I've also read
>> that on windoze, it can cause a system to freeze while it is trying
>> to rewrite the moved data too.  It gets so slow, it actually makes
>> the OS not respond.  I suspect it could happen on Linux to if the
>> conditions are right.
>>
> Being all technical, what seems to be happening is ...
>
> Random writes fillup the PMR cache. The drive starts flushing the
> cache, but unfortunately you need a doubly linked list or something -
> you need to be able to find the physical block from the logical
> address (for reading) and to find the logical block from the physical
> address (for cache-flushing). So once the cache fills, the drive needs
> "down time" to move stuff around, and it stops responding to the bus.
> There are reports of disk stalls of 10 minutes or more - bear in mind
> desktop drives are classed as unsuitable for raid because they stall
> for *up* *to* *two* minutes ...
>
>> I guess this is about saving money for the drive makers.  The part
>> that seems to really get under peoples skin tho, them putting those
>> drives out there without telling people that they made changes that
>> affect performance.  It's bad enough for people who use them where
>> they work well but the people that use RAID and such, it seems to
>> bring them to their knees at times.  I can't count the number of
>> times I've read that people support a class action lawsuit over
>> shipping SMR without telling anyone.  It could happen and I'm not
>> sure it shouldn't.  People using RAID and such, especially in some
>> systems, they need performance not drives that beat themselves to death.
>
> Most manufacturers haven't been open, but at least - apart from WD -
> they haven't been stupid either. Bear in mind WD actively market their
> Red drives as suitable for NAS or Raid, putting SMR in there was
> absolutely dumb. Certainly in the UK, as soon as news starts getting
> round, they'll probably find themselves (or rather their retailers
> will get shafted with) loads of returns as "unfit for purpose". And,
> basically, they have a legal liability with no leg to stand on because
> if a product doesn't do what it's advertised for, then the customer is
> *entitled* to a refund.
>
> Dunno why, I've never been a WD fan, so I dodged that bullet. I just
> caught another one, because I regularly advise people they shouldn't
> be running Barracudas, while running two myself ... :-)
>
> Cheers,
> Wol
>
>


From what I've read, all the drive makers were selling SMR without
telling anyone at first.  It wasn't just WD but Seagate as well.  There
was another maker as well but can't recall what the brand was.  I want
to say HGST but could have been something else.  I tend to like WD and
Seagate and have had a couple Toshibas as well.  I've had a WD go bad
but I've had a Seagate go bad too.  I'm of the mindset that most drives
are good but on occasion, you hit a bad batch.  No matter what brand it
is, there is a horror story out there somewhere.  I've been lucky so
far.  It seems SMART catches that a drive is failing before it actually
does.  I had one that gave the 24 hour warning and it wasn't kidding
either.  Another just starting reporting bad spots.  I replaced it
before it corrupted anything.  I've never lost data that I can recall tho. 

I've read that if there is a lawsuit, the EU will likely be first and
the easiest.  If you say something should work in a certain way and it
doesn't, refund for sure.  Given the large scale of this, lawsuit is
possible.  I'm no lawyer but I do think what the makers did in hiding
this info is wrong.  It doesn't matter what brand it is, they should be
honest about their products.  This is especially true for situations
like RAID, NAS and other 24/7 systems.  Thing is, even my system falls
into that category.  I run 24/7 here except during power failures.  LVM
likely requires a better drive than a regular home type system that is
only used a little each day.  Commercial type systems that are in heavy
use, they require a really heavy duty components.  Claiming something is
or leaving out info that shows they are not is not good.  They should
have known it would bite them at some point.  People have far to many
tools to test drives and uncover the truth. 

Little update.  The drive passed its first SMART long test.  I started
badblocks hours ago and it is almost done.  It's at 96% right now.  I
think it lists bad blocks as it finds them and so far, it hasn't listed
any.  I'll post the results when it is done.  So far, the drive I bought
seems to be in very good condition. 

Now to wait on the last little bit to finish.  Just hope it doesn't get
right to the end and start blowing smoke.  :/

Dale

:-)  :-)