On 14/06/11 02:30, Tim Blundell wrote:
On 6/11/2011 5:49 AM, Mathias BurÃn wrote:
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Caviar Green (Adv. Format) family
Device Model: WDC WD20EARS-00MVWB0
Serial Number: WD-WMAZ20188479
Firmware Version: 50.0AB50
User Capacity: 2,000,398,934,016 bytes
Device is: In smartctl database [for details use: -P show]
ATA Version is: 8
ATA Standard is: Exact ATA specification draft version not indicated
Local Time is: Sat Jun 11 10:48:05 2011 IST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
Not certain if this was mentioned. While WDC WD20EARS drives can be used in an RAID array, WD
recommends using there RAID capable drives in an enterprise environment.
I tried using same drives in a simple RAID-1 array and had serious performance issues (sync taking
a week) and stalls when writing to disk. Are you using the stock firmware on these drives?
Just a data point. I have 10 of them in a RAID-6. They are in a 6 core / 16GB box with PCIe SAS
controllers (so the machine is not bandwidth starved). I hammer the living daylights out of them.
They are quite fast for sequential access, not very fast for random IO and they are pretty cool and
quiet.
I have used WDIDLE3 to turn off the idle timer to stop the heads unloading though.
The reason WD state their consumer drives are no good in RAID applications is TLER. On a hardware
RAID controller the drives can get kicked out of the array if they go into a deep recovery read, but
md does not suffer this issue.
On SMART, it's prudent to configure smartmontools to do regular checks and e-mail you if it sees an
issue. I do a long every sunday and shorts every other morning and have had early notification of
pending issues a couple of times. Definitely worth the price of admission.
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