From owner-freebsd-questions Mon Jan 14 23:11:47 2002 Delivered-To: freebsd-questions@freebsd.org Received: from andrsn.stanford.edu (andrsn.Stanford.EDU [171.66.112.163]) by hub.freebsd.org (Postfix) with ESMTP id E0B5537B400 for ; Mon, 14 Jan 2002 23:11:43 -0800 (PST) Received: from localhost (andrsn@localhost.stanford.edu [127.0.0.1]) by andrsn.stanford.edu (8.9.3/8.9.1) with ESMTP id XAA53122; Mon, 14 Jan 2002 23:02:48 -0800 (PST) Date: Mon, 14 Jan 2002 23:02:48 -0800 (PST) From: Annelise Anderson To: Mike Meyer Cc: Alex.Wilkinson@dsto.defence.gov.au, freebsd-questions@FreeBSD.ORG Subject: Re: Super Block In-Reply-To: <15427.39528.11439.547654@guru.mired.org> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, 14 Jan 2002, Mike Meyer wrote: > > What does the SuperBlock actually do ? > > Why is the SuperBlock so critical ? > > > > Can anyone give me a *good* summary on the purpose of the Super Block ? > > And/Or any recommendations ? > > man fs. That will show you what's actually in the superblock, as well > as a longer description. > > One-sentence summary of why it's important: It where you start when > you want to find a file in the file system. Suppose you overwrite a disklabel and haven't made a copy; if you can access the slice and you want to write a new disklabel, is there any way to find out where the superblocks are? I damaged a disklabel (but have another installation of FreeBSD on the same IDE hard drive) and would like to rewrite the disklabel, of which I don't have a copy. The a partition shows up and I can write a file to use to label the disk; it was partitioned into a, b, and e (/ and swap and /usr). I can even "swapon" the b swap. However I don't seem to get the sizes right so that the superblock is found by e, and fsck refuses to run, because it can't find the superblock. Any solutions, other than being more careful with disklabels and making copies of them? Annelise -- Annelise Anderson Author of: FreeBSD: An Open-Source Operating System for Your PC Available from: BSDmall.com and amazon.com Book Website: http://www.bittreepress.com/FreeBSD/introbook/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message