From: Andreas Dilger Subject: Re: [RFC][Patch 2/2] Persistent preallocation in ext4 Date: Tue, 19 Dec 2006 14:14:09 -0700 Message-ID: <20061219211409.GP5937@schatzie.adilger.int> References: <20061205134338.GA1894@amitarora.in.ibm.com> <20061215123920.GB24572@amitarora.in.ibm.com> <20061219114251.GA25086@amitarora.in.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, suparna@in.ibm.com, cmm@us.ibm.com, suzuki@in.ibm.com, alex@clusterfs.com Return-path: Received: from mail.clusterfs.com ([206.168.112.78]:42567 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932936AbWLSVOM (ORCPT ); Tue, 19 Dec 2006 16:14:12 -0500 To: "Amit K. Arora" Content-Disposition: inline In-Reply-To: <20061219114251.GA25086@amitarora.in.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Dec 19, 2006 17:12 +0530, Amit K. Arora wrote: > I wrote a simple tool to test these patches. The tool takes four > arguments: > > * command: It may have either of the two values - "prealloc" or "write" > * filename: This is the filename with relative path > * offset: The offset within the file from where the preallocation, or > the write should start. > * length: Total number of bytes to be allocated/written from offset. > > Following cases were tested : > 1. * preallocation from 0 to 32MB > * write to various parts of the preallocated space in sets > * observed that the extents get split and also get merged > > 2. * preallocate with holes at various places in the file > * write to blocks starting from a hole and ending into preallocated > blocks and vice-versa > * try to write to entire set of blocks (i.e. from 0 to the last > preallocated block) which has holes in between. An ideal test would be to modify fsx to (randomly) do preallocations instead of truncates that increase the size. Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.