From owner-freebsd-fs Tue Apr 30 9:36:18 2002 Delivered-To: freebsd-fs@freebsd.org Received: from scaup.prod.itd.earthlink.net (scaup.mail.pas.earthlink.net [207.217.120.49]) by hub.freebsd.org (Postfix) with ESMTP id B9D6B37B41D for ; Tue, 30 Apr 2002 09:36:10 -0700 (PDT) Received: from pool0495.cvx21-bradley.dialup.earthlink.net ([209.179.193.240] helo=mindspring.com) by scaup.prod.itd.earthlink.net with esmtp (Exim 3.33 #2) id 172abi-0002fb-00; Tue, 30 Apr 2002 09:36:02 -0700 Message-ID: <3CCEC7D5.D22356A0@mindspring.com> Date: Tue, 30 Apr 2002 09:35:33 -0700 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: "Andrew P. Lentvorski" Cc: freebsd-fs@freebsd.org Subject: Re: Non-standard root filesystems References: <20020429153020.Q16532-100000@mail.allcaps.org> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org FreeBSD treats root mounts as "special", relative to all other mounts. This is a design error, but overcoming it requires a reorganization of the mount code that's not really politically easy to accomplish, even though it's technically very easy. Some of the stuff Poul is doing right now will probably help you in the future with assembing things like RAID-able volumes in the future -- but not help you right now. As far as software RAID is concerned: it's a bad idea, from a performance perspective; I don't recommend it. Note that I'm the person who did the original user space RAIDframe port to FreeBSD in the mid 1990's, so I'm not just talking out my butt: the amount of overhead for parity calculation and storage is *considerable*, and makes RAID hardware a *much* better idea. -- Terry "Andrew P. Lentvorski" wrote: > > Could someone fill me in on the current status of either A) remounting a > root filesystem or B) mounting a non-standard fs as a root fs? > > I've bumped into this three times now. Twice as part of the vinum stuff > and a third as part of a solid-state media problem. In the case of vinum, > I actually had a client choose a Linux system because its rootfs is > software RAIDable. > > Other people are also starting to bump into the issue as brought up in the > NFS attribute thread. (AFS can't be used because the root filesystem > can't be remounted completely) > > What is the current status? Or, alternatively, what are the issues with > implementation? Is it a political problem (no perceived need/low > priority/coming in FreeBSD 5.X) or is it a massive amount of work problem? > > Thanks, > -a > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-fs" in the body of the message To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message