From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brad Campbell Subject: Re: HDD reports errors while completing RAID6 array check Date: Tue, 14 Jun 2011 08:15:32 +0800 Message-ID: <4DF6A824.6070502@fnarfbargle.com> References: <20110611000000.76ca58e7@natsu> <4DF65758.2030405@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4DF65758.2030405@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Linux-RAID List-Id: linux-raid.ids On 14/06/11 02:30, Tim Blundell wrote: > > On 6/11/2011 5:49 AM, Mathias Bur=C3=A9n wrote: >> =3D=3D=3D START OF INFORMATION SECTION =3D=3D=3D >> 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 indicate= d >> 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 u= sed in an RAID array, WD=20 > recommends using there RAID capable drives in an enterprise environme= nt. > I tried using same drives in a simple RAID-1 array and had serious pe= rformance issues (sync taking=20 > a week) and stalls when writing to disk. Are you using the stock firm= ware 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=20 controllers (so the machine is not bandwidth starved). I hammer the liv= ing daylights out of them.=20 They are quite fast for sequential access, not very fast for random IO = and they are pretty cool and=20 quiet. I have used WDIDLE3 to turn off the idle timer to stop the heads unload= ing though. The reason WD state their consumer drives are no good in RAID applicati= ons is TLER. On a hardware=20 RAID controller the drives can get kicked out of the array if they go i= nto a deep recovery read, but=20 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=20 issue. I do a long every sunday and shorts every other morning and have= had early notification of=20 pending issues a couple of times. Definitely worth the price of admissi= on. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html