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

[Gregory Youngblood]

On Aug 6, 2011, at 9:56 AM, Roy Sigurd Karlsbakk wrote:

>> In my experience, SATA drives behind SAS expanders just don't work.
>> They "fail" in the manner you
>> describe, sooner or later. Use SAS and be happy.
> 
> Funny thing is Hitachi and Seagate drives work stably, whereas WD drives tend to fail rather quickly
> 
> Vennlige hilsener / Best regards

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 (?).

Greg