From: Karel Zak Subject: Re: [dm-devel] do not disable ext4 discards on first discard failure? [was: Re: dm snapshot: ignore discards issued to the snapshot-origin target] Date: Thu, 5 May 2011 10:33:44 +0200 Message-ID: <20110505083344.GA1114@nb.net.home> References: <20110429122454.GL32370@agk-dp.fab.redhat.com> <20110502081308.GC8642@agk-dp.fab.redhat.com> <20110502081925.GA11312@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: Lukas Czerner , Christoph Hellwig , device-mapper development , Alasdair G Kergon , sandeen@redhat.com, Mike Snitzer , DarkNovaNick@gmail.com, linux-lvm@redhat.com, linux-ext4@vger.kernel.org To: "Martin K. Petersen" Return-path: Received: from mx1.redhat.com ([209.132.183.28]:5032 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753137Ab1EEIeC (ORCPT ); Thu, 5 May 2011 04:34:02 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: On Wed, May 04, 2011 at 11:16:05AM -0400, Martin K. Petersen wrote: > >>>>> "Lukas" =3D=3D Lukas Czerner writes: >=20 > I got tired of poking around in sysfs to find the discard topology. > Here's a patch against lsblk that adds a -D option to present this > information in a human-readable form: Applied, thanks. > # lsblk -D > NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO > sda 0 0B 0B 0 > =E2=94=94=E2=94=80sda1 0 0B 0B = 0 > sdb 0 512B 2G 1 > =E2=94=94=E2=94=80sdb1 0 512B 2G = 1 I have a question, 2.6.35 on my ThinkPad, non-SSD disk: NAME DISC-ALN DISC-GRAN DISC-MAX DISC-ZERO sda 0 0B 0B 0 =E2=94=9C=E2=94=80sda1 4294935040 0B 0B = 0 =E2=94=9C=E2=94=80sda2 4188038656 0B 0B = 0 =E2=94=9C=E2=94=80sda3 1346205184 0B 0B = 0 =E2=94=9C=E2=94=80sda4 3231165440 0B 0B = 0 =E2=94=9C=E2=94=80sda5 4188006400 0B 0B = 0 =E2=94=82 =E2=94=94=E2=94=80kzak-home (dm-0) 0 0B = 0B 0 =E2=94=94=E2=94=80sda6 2035725312 0B 0B = 0 Does is make sense? The DISC-ALN is non-zero but DISC-GRAN is zero. Note that cat /sys/block/sda/sda*/discard_alignment returns the same numbers. Karel --=20 Karel Zak http://karelzak.blogspot.com -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html