From: Lukas Czerner 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 12:48:41 +0200 (CEST) Message-ID: References: <20110429122454.GL32370@agk-dp.fab.redhat.com> <20110502081308.GC8642@agk-dp.fab.redhat.com> <20110502081925.GA11312@infradead.org> <20110505083344.GA1114@nb.net.home> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-61399738-1304592526=:3760" Cc: "Martin K. Petersen" , 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: Karel Zak Return-path: Received: from mx1.redhat.com ([209.132.183.28]:9631 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753535Ab1EEKs7 (ORCPT ); Thu, 5 May 2011 06:48:59 -0400 In-Reply-To: <20110505083344.GA1114@nb.net.home> Sender: linux-ext4-owner@vger.kernel.org List-ID: This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-61399738-1304592526=:3760 Content-Type: TEXT/PLAIN; charset=utf-8 Content-Transfer-Encoding: 8BIT On Thu, 5 May 2011, Karel Zak wrote: > On Wed, May 04, 2011 at 11:16:05AM -0400, Martin K. Petersen wrote: > > >>>>> "Lukas" == Lukas Czerner writes: > > > > 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 > > └─sda1 0 0B 0B 0 > > sdb 0 512B 2G 1 > > └─sdb1 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 > ├─sda1 4294935040 0B 0B 0 > ├─sda2 4188038656 0B 0B 0 > ├─sda3 1346205184 0B 0B 0 > ├─sda4 3231165440 0B 0B 0 > ├─sda5 4188006400 0B 0B 0 > │ └─kzak-home (dm-0) 0 0B 0B 0 > └─sda6 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 > > That is fixed by the kernel patch posted above :) -Lukas --8323328-61399738-1304592526=:3760--