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Date: Tue, 22 Mar 2011 11:23:22 +0100
From: Karel Zak <kzak@redhat.com>
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Subject: Re: [linux-lvm] Advanced Format disks mixed with regular disks?
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To: LVM general discussion and development <linux-lvm@redhat.com>

On Thu, Mar 17, 2011 at 06:47:18PM -0500, Ron Johnson wrote:
> On 03/16/2011 07:39 PM, Martin K. Petersen wrote:
>>>>>>> "Phillip" == Phillip Susi<psusi@cfl.rr.com>  writes:
>>
>> Phillip>  The kernel has the ability to read it from the drive and report
>> Phillip>  it to the user space tools, which have been patched to use it,
>> Phillip>  but the WD EARS drives lie and claim 512/512 instead of
>> Phillip>  512/4096.
>>
>> The saving grace is that modern util-linux/dm tooling aligns on 1MB by
>> default instead of sector 63.
>>
>
> So, given the correct options ( -c -b 4096 ), v2.17.2 will handle the 2TB 
> WD Caviar Green WD20EARS drives which I just bought for my external 
> backup device...  Right?

The -b option is usually unnecessary (for v2.17 is the -c enough).

It seems (according to feedback from users) that newer WDxxEARS disks
are already fixed. 
http://community.wdc.com/t5/Desktop/Problem-with-WD-Advanced-Format-drive-in-LINUX-WD15EARS/m-p/20675#M1245


Try

  hdparm -I /dev/<disk>

to see more details, for example:

    Logical  Sector size:                   512 bytes
    Physical Sector size:                  4096 bytes

and
 
   # cat /sys/block/<disk>/queue/physical_block_size
   4096


It's also better to update to util-linux v2.18 or v2.19 where all the
new features are enabled by default (so -c is unnecessary too).

    Karel

-- 
 Karel Zak  <kzak@redhat.com>
 http://karelzak.blogspot.com