From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx12.extmail.prod.ext.phx2.redhat.com [10.5.110.17]) by int-mx02.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id qBEIqf1X025047 for ; Fri, 14 Dec 2012 13:52:41 -0500 Received: from mail.bmsi.com (www.bmsi.com [24.248.44.156]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id qBEIqefu006762 for ; Fri, 14 Dec 2012 13:52:41 -0500 Received: from sdg.bmsi.com (sdg.bmsi.com [192.168.9.34] (may be forged)) (authenticated bits=0) by mail.bmsi.com (8.14.3/8.14.3) with ESMTP id qBEIqdpr004660 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Fri, 14 Dec 2012 13:52:40 -0500 Message-ID: <50CB7577.4050906@bmsi.com> Date: Fri, 14 Dec 2012 13:52:39 -0500 From: Stuart D Gathman MIME-Version: 1.0 References: <50C9F2D6.7090802@ubuntu.com> In-Reply-To: <50C9F2D6.7090802@ubuntu.com> Content-Transfer-Encoding: 7bit Subject: Re: [linux-lvm] Non 512 byte sectors Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: linux-lvm@redhat.com On 12/13/2012 10:23 AM, Phillip Susi expounded in part: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Is it possible to get dm to report > 512 byte sector size? If so, how? > > blockdev --getss /dev/vg/lv (or any other block device) That is probably logical sector size, however. The only way I know to get physical sector size is: hdparm -I /dev/sda which reports logical and physical sector size. Some WD devices are known to lie about physical sector size, however. If you always align stuff to 4096, there won't be a problem. In fact, new technology tends to have much larger alignment requirements for optimum performance - say 128k, the size of an erase block, or 64k for a RAID chunk size. So aligning everything to 1M should hold you for a while.