From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by mail.saout.de (Postfix) with ESMTP for ; Thu, 2 Dec 2010 12:44:16 +0100 (CET) Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oB2BiFla016854 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 2 Dec 2010 06:44:15 -0500 Received: from [10.36.4.80] (vpn1-4-80.ams2.redhat.com [10.36.4.80]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id oB2BiETb011868 for ; Thu, 2 Dec 2010 06:44:15 -0500 Message-ID: <4CF7868D.4040404@redhat.com> Date: Thu, 02 Dec 2010 12:44:13 +0100 From: Milan Broz MIME-Version: 1.0 References: <20101201145123.GA10238@dentifrice> <20101202075413.GE19274@maude.comedia.it> In-Reply-To: <20101202075413.GE19274@maude.comedia.it> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Subject: Re: [dm-crypt] status of dm-crypt (alignment issues) on a SSD List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de On 12/02/2010 08:54 AM, Luca Berra wrote: > what you need on kernel side is having in sysfs > under /sys/block/ > queue/minimum_io_size > queue/optimal_io_size > queue/physical_block_size Just not all SSD presents proper values here. My advice is align to 1MiB in such case and it will work:-) (this is default in recent versions - not all yet in Debian) You can always do it manually, use fdisk -u (to work in sector mode, note sector is 512B. Switch off DOS mode if it is enabled - there should be warning) For lvm, use pvcreate --dataalignment, then check with pvs -o +pe_start. (You can use --units S to work in sectors mode like in fdisk. 2048 sectors == 1MiB, any multiple of it is ok) (See man page and check archive, I think it was described here several times.) Milan