From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay2.corp.sgi.com [137.38.102.29]) by oss.sgi.com (Postfix) with ESMTP id 946117F37 for ; Tue, 15 Dec 2015 07:16:16 -0600 (CST) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay2.corp.sgi.com (Postfix) with ESMTP id 75527304039 for ; Tue, 15 Dec 2015 05:16:13 -0800 (PST) Received: from mail-wm0-f41.google.com (mail-wm0-f41.google.com [74.125.82.41]) by cuda.sgi.com with ESMTP id BfkYYJDDeMol6fSy (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NO) for ; Tue, 15 Dec 2015 05:16:11 -0800 (PST) Received: by mail-wm0-f41.google.com with SMTP id n186so93951747wmn.0 for ; Tue, 15 Dec 2015 05:16:11 -0800 (PST) Received: from sauron (agpz34.neoplus.adsl.tpnet.pl. [217.99.25.34]) by smtp.gmail.com with ESMTPSA id c4sm1379131wjs.36.2015.12.15.05.16.09 for (version=TLSv1/SSLv3 cipher=OTHER); Tue, 15 Dec 2015 05:16:09 -0800 (PST) Date: Tue, 15 Dec 2015 14:16:05 +0100 From: =?UTF-8?B?TWljaGHFgg==?= Pecio Subject: Fixing XFS RAID - does XFS ever issue non-aligned discards? Message-ID: <20151215141605.5b60d336@sauron> MIME-Version: 1.0 List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Hi, I'm using XFS with bsize=4096 on RAID0 of two Intel 320 SSDs under Linux 3.18 LTS. I'm wondering if it's correct to assume that discards issued by XFS will always be multiples of 4k and 4k-aligned? I'm asking because I need to fix damage caused by the infamous RAID0 bug from May 2015, which, if I'm reading the code correctly, basically permuted discard requests between component disks, i.e. sda discarded offsets which were supposed to be discarded by sdb and vice-versa. The only backup I have is very slow so I'm trying to minimize copying. The list of files with 4k-aligned blocks of zeros is small and worth reviewing manually, but there is much more files with smaller holes and I'd like to know if I should be bothered by them. Fwiw, I checked few and they've all been false positives so far. Thanks for any help, MP _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs