From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: with ECARTIS (v1.0.0; list xfs); Tue, 11 Dec 2007 14:16:05 -0800 (PST) Received: from larry.melbourne.sgi.com (larry.melbourne.sgi.com [134.14.52.130]) by oss.sgi.com (8.12.11.20060308/8.12.11/SuSE Linux 0.7) with SMTP id lBBMFtvx002837 for ; Tue, 11 Dec 2007 14:16:00 -0800 Date: Wed, 12 Dec 2007 09:15:55 +1100 From: David Chinner Subject: Re: mkfs.xfs ... lazy-count=1 ... not mountable by older kernels? Message-ID: <20071211221554.GC4612@sgi.com> References: <475EE83A.3060607@ca.sophos.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <475EE83A.3060607@ca.sophos.com> Sender: xfs-bounce@oss.sgi.com Errors-to: xfs-bounce@oss.sgi.com List-Id: xfs To: David Sparks Cc: xfs@oss.sgi.com On Tue, Dec 11, 2007 at 11:42:50AM -0800, David Sparks wrote: > Hi all, > > Is it expected that filesystems made with lazy-count=1 are not mountable by > older kernels? That is expected. lazy-count is a mkfs option because it changes the on-disk format slightly, and older kernels do not understand that format. Hence mkfs sets a superblock feature bit to prevent the filesystem from being mounted on kernels that don't understand the slightly different disk format. Cheers, Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group