From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o7CMAGkk254317 for ; Thu, 12 Aug 2010 17:10:17 -0500 Received: from isrv.corpit.ru (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 0FC3B14CDC41 for ; Thu, 12 Aug 2010 15:19:30 -0700 (PDT) Received: from isrv.corpit.ru (isrv.corpit.ru [86.62.121.231]) by cuda.sgi.com with ESMTP id OJAvY0iEXroFrJKS for ; Thu, 12 Aug 2010 15:19:30 -0700 (PDT) Message-ID: <4C64715F.8060000@msgid.tls.msk.ru> Date: Fri, 13 Aug 2010 02:10:39 +0400 From: Michael Tokarev MIME-Version: 1.0 Subject: Alignment size? 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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com Hello. I used XFS for a long time on many different servers, and it works well. But now I encountered an.. unexpected problem. The question is: on one of our servers, XFS requires different alignment size for O_DIRECT operations than on others. Usually it's 512 bytes, but on this server it is 4096 - both min_io and alignment (this is from XFS_IOC_DIOINFO ioctl). I'm not sure what the reason for this is. On this server, the underlying block device is raid5 (linux sw raid), but we had other machines with raid5 which didn't have that alignment requiriments. The problem with that is that Oracle db, which we use with XFS alot, refuses to work on this machine, or, rather, XFS refuses to process I/O in 512-byte chunks from oracle (control files and redolog files). I know it is a frequent combination which is used in production in many places, and is used here alot too, but I haven't seen anyone mentioning this issue we have now, with "larger than usual" alignment size requiriments. Is there a way to remedy this somehow, without reformatting whole 600+ gb? Thank you! /mjt _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs