[CentOS] Re: Disk near failure

[Yamaban]

On Fri, 28 Oct 2016 18:50, Alessandro Baggi wrote:
> Il 28/10/2016 16:28, Valeri Galtsev ha scritto:
>>  On Fri, October 28, 2016 2:42 am, Alessandro Baggi wrote:
>> >  Il 27/10/2016 19:38, Yamaban ha scritto:
>> > >  For my personal use I would replace that Drive asap.
>> > >  - There is no warranty for it anymore (time since buy)
>> > >  - You can't buy it new anymore (discontinued)
>> > >  - There are more reliable drives available.
>> > > 
>> > >  I'd go for a Samsung Evo 850, that will give you five years of 
>> > >  warranty.
>> > > 
>> > >  But, it's your drive, you make the decissions.
>> > > 
>> > >   - Yamaban.
>> > 
>> >  Thank you for your suggestion.
>> > 
>> >  What do you think about Corsair Neutron XTi 240 MLC?
>> > 
>>
>>  Amazing. He suggested you definitely reliable drive (Samsung). Reliable in
>>  my boot too. You ask his opinion about yet another Corsair. One by Corsair
>>  failed on you already. So, you should have better knowledge about
>>  Corsair's SSD reliability, right?
>>
>>  Sorry to sound sour, it just amuses me how people keep buying things made
>>  by the same company whose products already failed on them. This is what
>>  creates the problem: keeps companies manufacturing bad hardware exist.
[snip]
>
> Sorry, but my 2 ssds corsair does not report error and works fine, with good 
> performances and without realloc. These disks are not failed. Yes, they are 
> failing but these are old driver and this is a desktop under raid. Consider 
> that these drive are 5 years old, for me this is not bad ssd brand, there are 
> best brand but corsair is not too bad.
>
> Now, Yamaban had suggested samsung because this is the best choice. This does 
> not exclude that there are other products (that can be less reliable and less 
> performant at lower cost) that for my case are good enough. Corsair neutron 
> has also 5 years of warrenty.
>
>>  Sorry to sound sour, it just amuses me how people keep buying things made
>>  by the same company whose products already failed on them. This is what
>>  creates the problem: keeps companies manufacturing bad hardware exist.
>> 
>
> If you are AMD user and your old AMD cpu died, You think that AMD must burn 
> due to a cpu failure? Great.
> I'm with you in the case where you buy a disk and after 3/6 months it fails 
> (and this can happen also with very good brand) and this is not the case. 
> Backblaze must burn all brand because many disks fails....
>
> Now about bad hardware manufacturing companies it's another problem. These 
> companies point to low cost consumer, due the fact that not anyone can get the 
> best hardware due to money. An example? Corsair LE 480 GB (100$) vs  Samsung 
> SSD Serie 850 Pro 512GB (260$). 850 Pro is better, but more expensive, and 
> Corsair LE has 3 year of warrenty. Maybe an user can spend his money  for a 
> vga or a better cpu. These bad companies permit some users to get hw for less 
> money without a great expecation for cheapest use case and their ability to 
> pay.
>
> Than if these cheap companies must not exist, the user must not use a new 
> technology (at lower cost)? The IT gap.
>
> Sorry, my (m.)2 cents.

I'm VERY unsure how to answer on "The Question" of what SSD to buy.
Religious wars have been fought over less.

So, I'll give a intro on how I select a product for myself, and a view
into how I personally priorise specification requirements.

- Reliability. A "new" Technology (e.g. SLC -> MLC -> TLC) has to be on
   the market for at least a year as a 3-5 year warranty customer product,
   or at least 3 month on the market as a 5-10 year warranty datacenter one.

- Thrustworthyness. How does the manufacturer handle a product gaffe?
   * Denial, delay, FUD -> drop that manufacturer, not worthy at all.
   * Acceptance of proof, offer of upwards replacement -> good, keep.

- Openness on product specification.
   Full specs should be available on manufacturer web site at no cost.
   Proof of specs by testing of not-paid-for-it Third party? Good!


In your case, be very thankfull that you got 5 years out of the disks,
not may got that.

After some datalosses due to sudden drive failure, I'm replaceing my
drives after ca 3 years at similar runtime ("on"-time hours), and that
is why I encurage you to replace your drive. Not to drive the economy.

In the past "Corsair" was a power enthusiast product, and the time-cycle
for those "enthusiast" was 2 to 3 years. No problem for most of the
"Corsair" products.

With view on SSD you have to seperate the classes / groups:
1. Datacenter: 100% on time, 100% backup, failure time is very expensive.
2. Professional: 30-100% on time, 80-100% backup, dataloss is expensive.
3. Longtime User: 15-100% on time, 15-100% backup, dataloss is hassle.
4. Power-Enthusiast: 100% Speed, Backup? -- Can you eat that?
5. "Walmart" and Co: some speed, some use time, dataloss is your problem.

(Prices are for Europe, Germany, online buy)

The "Samsung SSD 850 Pro" with 10year warranty, 2. group, 256GiB ~ 125€
The "Samsung SSD 850 Evo" with 5 year warranty, 3. group, 250GiB ~  90€
The "Corsair Neutron XTi" with 5 year warranty, 3. group, 240GiB ~ 100€
The "Corsair Force LE"    with 3 year warranty, 5. group, 240GiB ~  70€

>From the user standpoint, the difference between the Samsung SSD 850 Evo
and the Corsair Neutron XTi is not that big.
Samsung: TLC 3D Flash, 75TBW @ 250 Gib size, 1,5 Mh MTBF, 512MB Cache
Corsair: MLC 2D Flash, 160TBW @ 240 GiB size, ?? MTBF, no RAM-Cache

Either Corsair does not want to a) test for MTBF, b) show the MTBF, or
c) they are not really satisfied with it and thus hide it. *shrugs*


http://www.anandtech.com/show/9799/best-ssds
http://www.anandtech.com/show/10406/corsair-gives-phison-ps3110-s10-another-try-neutron-xti-ssds-launched

http://www.tomshardware.com/reviews/best-ssds,3891-2.html
http://www.tomshardware.com/reviews/corsair-neutron-xti-ssd-review,4599.html


My personal conclusion:
If you are comfortable with the "Corsair Neutron XTi", it will give you a
near same performance for most use-cases as the "Samsung SSD 850 Evo" does.

Years ago, when the "Samsung SSD 850 Evo" came out I was not convinced,
and went with a "Crucial M4", based on a gut-feeling. I got lucky,
it did hold for 3.5 years at 60% on, and got retired from daily use in
working condition. I still use ist for a fast transfer between open
PCs, 250 GiB USB sticks are still expensive.

thats my 2ct, YMMV.

  - Yamaban.