From owner-freebsd-hackers Tue Jul 23 7:53:24 2002 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 39BF837B400 for ; Tue, 23 Jul 2002 07:53:22 -0700 (PDT) Received: from dan.emsphone.com (dan.emsphone.com [199.67.51.101]) by mx1.FreeBSD.org (Postfix) with ESMTP id 98B0843E5E for ; Tue, 23 Jul 2002 07:53:21 -0700 (PDT) (envelope-from dan@dan.emsphone.com) Received: (from dan@localhost) by dan.emsphone.com (8.12.5/8.12.5) id g6NErE3u044471; Tue, 23 Jul 2002 09:53:14 -0500 (CDT) (envelope-from dan) Date: Tue, 23 Jul 2002 09:53:14 -0500 From: Dan Nelson To: dirkx@covalent.net Cc: krentel@dreamscape.com, peter@wemm.org, freebsd-hackers@FreeBSD.ORG Subject: Re: dump on mounted fs Message-ID: <20020723145314.GE82383@dan.emsphone.com> References: <200207190139.g6J1da517312@dreamscape.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-OS: FreeBSD 5.0-CURRENT X-message-flag: Outlook Error User-Agent: Mutt/1.5.1i Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In the last episode (Jul 21), dirkx@covalent.net said: > On Thu, 18 Jul 2002, Mark W. Krentel wrote: > > > Dump on a live FS is always risky. FreeBSD in 4.x and earlier > > > will have up to about a 30 second delay before a write() makes it > > > to physical disk. > > Is this regardless of the sync(8) command used ? And if so - what > does sync(8) actually sync - and which things are taking longer to > sync ? On a softupdates-mounted filesytem, all sync does is speed up the block-flushing clock a bit, I believe. It doesn't guarantee that unwritten data is flushed before the call returns. -- Dan Nelson dnelson@allantgroup.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message