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Message-ID: <4B95B5AC.8050101@gmail.com>
Date: Tue, 09 Mar 2010 11:42:52 +0900
From: Tejun Heo <htejun@gmail.com>
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To: Karel Zak <kzak@redhat.com>
CC: "Martin K. Petersen" <martin.petersen@oracle.com>,
       "linux-ide@vger.kernel.org" <linux-ide@vger.kernel.org>,
       lkml <linux-kernel@vger.kernel.org>,
       Daniel Taylor <Daniel.Taylor@wdc.com>, Jeff Garzik <jeff@garzik.org>,
       Mark Lord <kernel@teksavvy.com>, tytso@mit.edu,
       "H. Peter Anvin" <hpa@zytor.com>, hirofumi@mail.parknet.co.jp,
       Andrew Morton <akpm@linux-foundation.org>,
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       Matthew Wilcox <matthew@wil.cx>, aschnell@suse.de, knikanth@suse.de,
       jdelvare@suse.de, Jim Meyering <jim@meyering.net>
Subject: Re: ATA 4 KiB sector issues.
References: <4B947393.2050002@kernel.org> <yq1zl2ic058.fsf@sermon.lab.mkp.net> <20100308195847.GC18077@nb.net.home> <4B95B39C.70402@kernel.org>
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Hello, again.

On 03/09/2010 11:34 AM, Tejun Heo wrote:
>>  - parted uses 1MiB alignment for disks with unknown topology, disks
>>    with topology information are aligned to optimal (or minimum) I/O
>>    size (parted >= 2.1)
> 
> This will result in incorrect alignment for drives which lie about the
> physical sector size to work around BIOS/drivers issues (C-1).  It
> would probably be best to align to at least 1MiB.

I misread it.  C-1 would be disks w/o alignment information which will
be aligned to optimal_io_size which again would be 0 and thus 1MiB
alignment.  So, this should work, right?

Thanks.

-- 
tejun