[OpenIndiana-discuss] [zfs-discuss] Question about WD drives with Super Micro systems

[Mark]

On 07/08/2011 5:45 a.m., Roy Sigurd Karlsbakk wrote:
>> Might this be the SATA drives taking too long to reallocate bad
>> sectors? This is a common problem "desktop" drives have, they will
>> stop and basically focus on reallocating the bad sector as long as it
>> takes, which causes the raid setup to time out the operation and flag
>> the drive as failed. The "enterprise" sata drives, typically the same
>> as the high performing desktop drive, only they have a short timeout
>> on how long they are allowed to try and reallocate a bad sector so
>> they don't hit the failed drive timeout. Some drive firmwares, such as
>> older WD blacks if memory serves, had the ability to be forced to
>> behave like the enterprise drive, but WD updated the firmware so this
>> is longer possible.
>>
>> This is why you see SATA drives that typically have almost identical
>> specs, but one will be $69 and the other $139 - the former is a
>> "desktop" model while the latter is an "enterprise" or "raid" specific
>> model. I believe it's called different things by different brands:
>> TLER, ERC, and CCTL (?).
>
> I doubt this is about the lack of TLER et al. Some, or most, of the drives ditched by ZFS have shown to be quite good indeed. I guess this is a WD vs Intel SAS expanders issue
>
> Vennlige hilsener / Best regards
>
> roy
> --

The other overlooked thing is the different topology ie. native sata 
against sas translated sata and then sas expander as well.

I have had seagate ST3000641's just refuse to run with expanders, but 
work diecty connected to the sas controller.

It's funny how all this reminds me of fibre channel behaviour in it's 
early days.

Mark.