From owner-freebsd-arch Fri Dec 7 6:15:11 2001 Delivered-To: freebsd-arch@freebsd.org Received: from salmon.maths.tcd.ie (salmon.maths.tcd.ie [134.226.81.11]) by hub.freebsd.org (Postfix) with SMTP id 68A7037B405 for ; Fri, 7 Dec 2001 06:15:04 -0800 (PST) Received: from walton.maths.tcd.ie by salmon.maths.tcd.ie with SMTP id ; 7 Dec 2001 14:15:03 +0000 (GMT) To: Sheldon Hearn Cc: Matthew Dillon , Kirk McKusick , freebsd-arch@FreeBSD.ORG Subject: Re: Using a larger block size on large filesystems In-Reply-To: Your message of "Fri, 07 Dec 2001 15:35:34 +0200." <31807.1007732134@axl.seasidesoftware.co.za> Date: Fri, 07 Dec 2001 14:15:00 +0000 From: Ian Dowse Message-ID: <200112071415.aa41493@salmon.maths.tcd.ie> Sender: owner-freebsd-arch@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG In message <31807.1007732134@axl.seasidesoftware.co.za>, Sheldon Hearn writes: > >The only other thing I can think of is what obrien suggested. He told >me that it might be that people are wary of a filesystem that contains >only a single cylinder group, as this means you only have one >superblock. Just to clarify, each cylinder group has one backup superblock. This is in addition to the master superblock, so on a filesystem with just one cylinder group there will be 2 superblocks. However, the first backup superblock is located immediately after the master superblock, so some of the benefits of extra superblocks (fsck sanity tests, recovery from the begininning of a disk getting overwritten) are lost when there is just one cylinder group. Ian To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message