From owner-freebsd-questions@FreeBSD.ORG Fri Apr 25 18:29:24 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 8C6941065676 for ; Fri, 25 Apr 2008 18:29:24 +0000 (UTC) (envelope-from sonicy@otenet.gr) Received: from kane.otenet.gr (kane.otenet.gr [195.170.0.77]) by mx1.freebsd.org (Postfix) with ESMTP id 0A48F8FC1A for ; Fri, 25 Apr 2008 18:29:23 +0000 (UTC) (envelope-from sonicy@otenet.gr) Received: from joshua.ath.cx (athedsl-69915.home.otenet.gr [87.203.154.105]) (authenticated bits=0) by kane.otenet.gr (8.13.8/8.13.8/Debian-3) with ESMTP id m3PITLJw017981; Fri, 25 Apr 2008 21:29:21 +0300 Message-ID: <48122301.7090605@otenet.gr> Date: Fri, 25 Apr 2008 21:29:21 +0300 From: Manolis Kiagias User-Agent: Thunderbird 2.0.0.12 (X11/20080324) MIME-Version: 1.0 To: Joshua Isom References: <4810BCC4.9090401@otenet.gr> <29f21956e9b63b09ccadfd0a452fbfeb@gmail.com> In-Reply-To: <29f21956e9b63b09ccadfd0a452fbfeb@gmail.com> Content-Type: text/plain; charset=ISO-8859-7; format=flowed Content-Transfer-Encoding: 7bit Cc: "freebsd-questions@freebsd.org" Subject: Re: RFC: Article on implementing UFS journaling on desktop PCs X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 25 Apr 2008 18:29:24 -0000 Joshua Isom wrote: > > On Apr 24, 2008, at 12:00 PM, Manolis Kiagias wrote: > >> I have just completed an article (mostly how-to) for implementing UFS >> journaling on a typical desktop PC: >> >> http://store.itsyourftp.com/~sonic2000gr/freebsd/gjournal-desktop/article.html >> >> >> It focuses on detailing an easy to follow, repeatable procedure, to >> install FreeBSD on a typical PC and enable journaling on /usr and >> possibly /var. >> I am using this same procedure on my systems. >> >> I welcome all feedback, please send me any comments, suggestions and >> corrections. >> >> Thanks, >> Manolis >> _______________________________________________ >> freebsd-questions@freebsd.org mailing list >> http://lists.freebsd.org/mailman/listinfo/freebsd-questions >> To unsubscribe, send any mail to >> "freebsd-questions-unsubscribe@freebsd.org" >> >> > > "A kernel panic will occur if the journal space is exhausted before it > has a chance to be committed." > > So the intended behavior is for the kernel to give up(instead of keep > trying and maintain reliability), and risk data loss? With a > compliant hard drive that doesn't reorder writes, how is journaling > better than soft updates? > I was referring mainly to this post: http://lists.freebsd.org/pipermail/freebsd-questions/2008-April/173501.html Obviously I am no expert on the subject, but it seems to me that since the journal should keep the filesystem consistent, if it fills up and can't commit all the bits to disk, it would be better not to commit anything. Sure, you may lose data but not the filesystem. Having said that, the article only deals with the use of journaling on a typical desktop. I am already using default 1Gb journals on all my desktop systems (at least one works for a few hours under quite heavy load) and a home server for an individual who constantly copies several very large files over gigabit net (gjournal+gmirror in his case). I have never encountered any problem. YMMV, proceed with care.