From: Kalpak Shah Subject: Re: [PATCH 4/6] add noversion mount option Date: Fri, 15 Jun 2007 03:22:06 +0530 Message-ID: <1181857932.3926.4.camel@garfield> References: <1181835073.7779.9.camel@garfield> <1181836579.7779.46.camel@garfield> <1181854214.3883.10.camel@dyn9047017103.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: linux-ext4 , Andreas Dilger , Jean noel Cordenner To: cmm@us.ibm.com Return-path: Received: from mail.clusterfs.com ([206.168.112.78]:59289 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750984AbXFNVxV (ORCPT ); Thu, 14 Jun 2007 17:53:21 -0400 In-Reply-To: <1181854214.3883.10.camel@dyn9047017103.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Thu, 2007-06-14 at 13:50 -0700, Mingming Cao wrote: > On Thu, 2007-06-14 at 21:26 +0530, Kalpak Shah wrote: > > This patch adds a "noversion" mount option to disable inode version > > updates. > > Can you explain a bit more why we need this mount option? Is it because > of performance concern? Lustre requires the counter to be globally unique on the entire filesystem and hence needs to turnoff per-inode version updates. So in the interlock meeting on 5th June, Ted has suggested the this approach. "- Ted suggested having a flag in the superblock for i_version, with an additional option of having a global counter for Lustre's requirements. i_version would be on by default, but give users who do not use the feature the option to turn it off and avoid any performance impact." Thanks, Kalpak. > > Mingming > > - > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html