From owner-freebsd-stable Mon Apr 5 7:12:56 1999 Delivered-To: freebsd-stable@freebsd.org Received: from point.osg.gov.bc.ca (point.osg.gov.bc.ca [142.32.102.44]) by hub.freebsd.org (Postfix) with ESMTP id ED42B14EFB for ; Mon, 5 Apr 1999 07:12:54 -0700 (PDT) (envelope-from cy@cschuber.net.gov.bc.ca) Received: (from daemon@localhost) by point.osg.gov.bc.ca (8.8.7/8.8.8) id HAA11068; Mon, 5 Apr 1999 07:10:57 -0700 Received: from cschuber.net.gov.bc.ca(142.31.240.113), claiming to be "cwsys.cwsent.com" via SMTP by point.osg.gov.bc.ca, id smtpda11066; Mon Apr 5 07:10:44 1999 Received: (from uucp@localhost) by cwsys.cwsent.com (8.9.3/8.9.1) id HAA55376; Mon, 5 Apr 1999 07:10:42 -0700 (PDT) Message-Id: <199904051410.HAA55376@cwsys.cwsent.com> Received: from localhost.cwsent.com(127.0.0.1), claiming to be "cwsys" via SMTP by localhost.cwsent.com, id smtpdl55372; Mon Apr 5 07:10:37 1999 X-Mailer: exmh version 2.0.2 2/24/98 Reply-To: Cy Schubert - ITSD Open Systems Group From: Cy Schubert - ITSD Open Systems Group X-OS: FreeBSD 2.2.8-RELEASE X-Sender: cy To: Michael Haro Cc: stable@FreeBSD.ORG Subject: Re: How safe is NULLFS? In-reply-to: Your message of "Sun, 04 Apr 1999 23:54:35 PDT." <19990404235435.A37110@patrol.area51.fremont.ca.us> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 05 Apr 1999 07:10:36 -0700 Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In message <19990404235435.A37110@patrol.area51.fremont.ca.us>, Michael Haro wr ites: > Hi, I'd like to use NULLFS for a project I'm doing. The manpage for > mount_null has... > BUGS > THIS FILESYSTEM TYPE IS NOT YET FULLY SUPPORTED (READ: IT DOESN'T WORK) > AND USING IT MAY, IN FACT, DESTROY DATA ON YOUR SYSTEM. USE AT YOUR OWN > RISK. BEWARE OF DOG. SLIPPERY WHEN WET. > > I was wondering how dangerous this really is. If I'm using it to mount > part of my filesystem as read-only is there still a chance of harm to my > system? Should I just get another hard drive and majorly partition it > so I can get all the mounts where I want them and mount that drive > read-only everywhere needed? Basicly I'm trying to create a chrooted > copy of the base freebsd install which can be modified but while still > having the original copy. I guess what I want to do is mix NULLFS and > UNION together. I've been using nullfs and unionfs since 2.2.2. There are bugs in nullfs and unionfs, one of which supplys a zero to vfs that causes a divide by zero exception and panic. Take a look at PRs 5355, 5212, 5152, and 4491. IME, I haven't lost any data due to the use of nullfs and unionfs. Regards, Phone: (250)387-8437 Cy Schubert Fax: (250)387-5766 Open Systems Group Internet: Cy.Schubert@uumail.gov.bc.ca ITSD Cy.Schubert@gems8.gov.bc.ca Province of BC "e**(i*pi)+1=0" To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message