From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: Issue with md and 4K sector alignment Date: Thu, 06 Sep 2012 13:34:20 -0700 Message-ID: <504908CC.2030400@zytor.com> References: <5031556B.5050706@averageurl.com> <5031E72B.8060002@hesbynett.no> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5031E72B.8060002@hesbynett.no> Sender: linux-raid-owner@vger.kernel.org To: David Brown Cc: Mikael Abrahamsson , Kyle Brantley , linux-raid@vger.kernel.org List-Id: linux-raid.ids On 08/20/2012 12:28 AM, David Brown wrote: > > It would be nice if LVM and md moved towards a bigger native alignment. > 4K is good enough for hard disks, but for SSD's you want to align > partitions on erase block boundaries. The standard used by modern fdisk > and gparted (and tools from the-OS-that-must-not-be-named) is 1 MB - a > bigger alignment than is necessary for current SSDs, but one that will > be good enough for the foreseeable future. > This is one advantage with superblock 1.0 -- the alignment of the underlying device is preserved since the metadata is at the end. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.