From owner-freebsd-hackers@FreeBSD.ORG Wed Nov 17 20:29:34 2004 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 29C3B16A4CE for ; Wed, 17 Nov 2004 20:29:34 +0000 (GMT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id D256543D5C for ; Wed, 17 Nov 2004 20:29:33 +0000 (GMT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.13.1/8.13.1) id iAHKTQ2M071793; Wed, 17 Nov 2004 14:29:26 -0600 (CST) (envelope-from dan) Date: Wed, 17 Nov 2004 14:29:26 -0600 From: Dan Nelson To: David Gilbert Message-ID: <20041117202926.GG3342@dan.emsphone.com> References: <16795.45827.597456.957858@canoe.dclg.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16795.45827.597456.957858@canoe.dclg.ca> X-OS: FreeBSD 5.3-STABLE X-message-flag: Outlook Error User-Agent: Mutt/1.5.6i cc: freebsd-hackers@freebsd.org Subject: Re: Access time on snapshots. X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 17 Nov 2004 20:29:34 -0000 In the last episode (Nov 17), David Gilbert said: > Another odd thing about snapshots is that the time shown by ls -l is > mostly current. Havn't found a rule for that yet. ls -lu seems to > show the creation time even tho the man page for ls says that's the > last access time. > > Since the snapshot itself shouldn't (logically) change after > creation, it would seem sensible to make the modification time stay > constant. Could the mtime on the snapshot might be updated when the kernel has to add a block to the snapshot file because of a write to the parent filesystem? (note this only applies to the first write to a block; later writes don't affect the snapshot because it's already made a copy of the original data) > (also: why doesn't ls have a creation time option?) I think ls is running run out of option letters :) -- Dan Nelson dnelson@allantgroup.com