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 170C77F3F for ; Tue, 23 Sep 2014 19:46:43 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay2.corp.sgi.com (Postfix) with ESMTP id 05113304048 for ; Tue, 23 Sep 2014 17:46:39 -0700 (PDT) Received: from atvie01s.evermeet.cx (evermeet.cx [77.244.245.66]) by cuda.sgi.com with ESMTP id pAAVrkwyonDJ2QtJ (version=TLSv1 cipher=AES256-SHA bits=256 verify=NO) for ; Tue, 23 Sep 2014 17:46:37 -0700 (PDT) Received: from [10.0.0.40] (135-23-85-229.cpe.pppoe.ca [135.23.85.229]) (authenticated bits=0) by atvie01s.evermeet.cx (8.14.9/8.14.9) with ESMTP id s8O0kXKW008177 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Wed, 24 Sep 2014 02:46:34 +0200 Message-ID: <5422146A.90206@evermeet.cx> Date: Tue, 23 Sep 2014 20:46:34 -0400 From: Helmut Tessarek MIME-Version: 1.0 Subject: How to format RAID1 correctly 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 The information provided in the FAQ and on several web sites is not really useful regarding RAID1. According to the FAQ (entry 35): The correct options to format a RAID1 (2 disks) with 64k chunk size is: mkfs.xfs -d su=64k -d sw=1 /dev/mapper/data But it also states that it would be automatically detected and used correctly, yet mkfs.xfs /dev/mapper/data yields a different result: [root@atvie01s ~]# mkfs.xfs -f /dev/mapper/data meta-data=/dev/mapper/data isize=256 agcount=4, agsize=244173876 blks = sectsz=4096 attr=2, projid32bit=1 = crc=0 finobt=0 data = bsize=4096 blocks=976695504, imaxpct=5 = sunit=0 swidth=0 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal log bsize=4096 blocks=476902, version=2 = sectsz=4096 sunit=1 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 Formel 1: [root@atvie01s ~]# mkfs.xfs -f -d su=64k -d sw=1 /dev/mapper/data meta-data=/dev/mapper/data isize=256 agcount=32, agsize=30521728 blks = sectsz=4096 attr=2, projid32bit=1 = crc=0 finobt=0 data = bsize=4096 blocks=976695296, imaxpct=5 = sunit=16 swidth=16 blks naming =version 2 bsize=4096 ascii-ci=0 ftype=0 log =internal log bsize=4096 blocks=476902, version=2 = sectsz=4096 sunit=1 blks, lazy-count=1 realtime =none extsz=4096 blocks=0, rtextents=0 Another inconsistency is that RAID1 doesn't use striping, so the chunk size should be irrelevant in the first place. So what is ultimately the correct way to format a RAID1? Cheers, K. C. -- regards Helmut K. C. Tessarek lookup http://sks.pkqs.net for KeyID 0xC11F128D /* Thou shalt not follow the NULL pointer for chaos and madness await thee at its end. */ _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs