From mboxrd@z Thu Jan 1 00:00:00 1970 From: Milan Broz Subject: Bug#648367: [dm-devel] Bug#648367: device-mapper devices such as dm-crypt always have rotational=1; should inherit "rotational" setting from underlying devices Date: Tue, 15 Nov 2011 18:05:31 +0100 Message-ID: <4EC29BDB.8090803@redhat.com> References: <20111110195943.12083.93273.reportbug@leaf> <1321232729.3059.42.camel@deadeye> <20111114022644.GB30421@leaf> <4EC215FA.1090303@redhat.com> <20111115164151.GA24015@leaf> Reply-To: Milan Broz , 648367@bugs.debian.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: Resent-To: debian-bugs-dist@lists.debian.org Resent-Message-ID: In-Reply-To: <20111115164151.GA24015@leaf> List-Post: List-Help: List-Subscribe: List-Unsubscribe: To: Josh Triplett Cc: device-mapper development , Ben Hutchings , 648367@bugs.debian.org List-Id: dm-devel.ids On 11/15/2011 05:41 PM, Josh Triplett wrote: > I didn't know about that command; very nice, thanks! lsblk confirms > that on my system, the physical disk has rotational=3D0 but the dm-cryp= t > and LVM devices have rotational=3D1: >=20 > NAME ALIGNMENT MIN-IO OPT-IO PHY-SEC LOG-SEC ROTA SCH= ED > sda 0 512 0 512 512 0 cfq > =E2=94=9C=E2=94=80sda1 0 512 0 512 = 512 0 cfq > =E2=94=94=E2=94=80sda2 0 512 0 512 = 512 0 cfq > =E2=94=94=E2=94=80sda2_crypt (dm-0) 0 512 0 512 = 512 1=20 > =E2=94=9C=E2=94=80leaf-swap (dm-1) 0 512 0 512 = 512 1=20 > =E2=94=94=E2=94=80leaf-root (dm-2) 0 512 0 512 = 512 1=20 >=20 > Does that help? Thanks. As noted on that bug earlier, it is already fixed in 3.2-rc1 http://git.kernel.org/?p=3Dlinux/kernel/git/torvalds/linux.git;a=3Dcommit= diff;h=3D4693c9668fdcec229825b3763876b4744f9e6d5e (I thought it is fixed long time ago!) There is no problem in DM layer with this (dmcrypt does not have own io s= cheduler) but perhaps FS can use this flag for some optimization tuning, dunno. Milan