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Date: Thu, 26 Feb 2009 13:02:49 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: "Martin K. Petersen" <martin.petersen@oracle.com>
CC: Matthew Wilcox <matthew@wil.cx>, Theodore Tso <tytso@mit.edu>,
       linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org,
       sandeen@redhat.com
Subject: Re: ATA support for 4k sector size
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Martin K. Petersen wrote:
>>>>>> "hpa" == H Peter Anvin <hpa@zytor.com> writes:
> 
>>> Quick answer from one of my contacts.  Desktop drives will indeed
>>> ship with an alignment of 1(*).  The alignment is hardwired at time
>>> of manufacture and can't be changed.
>>>
> 
> hpa> Oh God.
> 
> hpa> This is a disaster.
> 
> Rationale being that modern Microsoft operating systems know how to
> interpret the alignment bits.  Legacy XP will work without changes
> thanks to the shifted alignment.  And Vista+ will do the right thing to
> align partition 1 to what the drive reports.
> 
> Also note that Windows only aligns the first partition.  That's
> something we need to be aware of when setting up dual boot systems.
> 

Yeah, but all of this completely breaks the disk image abstraction, 
which is a very powerful paradigm.

	-hpa