From: "Bradley C. Kuszmaul" Subject: Re: hole punching in ext4 Date: Tue, 22 Jan 2013 18:50:00 -0500 Message-ID: References: <20130122162009.GB2072@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: Zheng Liu , linux-ext4 Return-path: Received: from mail-ie0-f181.google.com ([209.85.223.181]:45361 "EHLO mail-ie0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752241Ab3AVXuW (ORCPT ); Tue, 22 Jan 2013 18:50:22 -0500 Received: by mail-ie0-f181.google.com with SMTP id 16so12607834iea.26 for ; Tue, 22 Jan 2013 15:50:22 -0800 (PST) In-Reply-To: <20130122162009.GB2072@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Thanks, this has been a very helpful thread. How do I determine and control whether a file is extent-based? -Bradley On Tue, Jan 22, 2013 at 11:20 AM, Zheng Liu wrote: > Ext4 file system supports hole punching. But until now only extent-based > file supports it. As far as I know, redhat distributions don't support > hole punching. You can find a sample program from e2fsprogs which is in > $e2fsprogs/conrib/fallocate.c. The latest fallocate(1) in util-linux > also can be as a demo.