From owner-freebsd-questions Mon Apr 17 17: 4:49 2000 Delivered-To: freebsd-questions@freebsd.org Received: from fedde.littleton.co.us (fedde.littleton.co.us [216.17.174.44]) by hub.freebsd.org (Postfix) with ESMTP id 6168637B75F for ; Mon, 17 Apr 2000 17:04:46 -0700 (PDT) (envelope-from cfedde@fedde.littleton.co.us) Received: from fedde.littleton.co.us (localhost [127.0.0.1]) by fedde.littleton.co.us (8.10.0/8.10.0) with ESMTP id e3I65Eh22956; Tue, 18 Apr 2000 00:05:14 -0600 (MDT) Message-Id: <200004180605.e3I65Eh22956@fedde.littleton.co.us> To: Salvo Bartolotta Cc: freebsd-questions@FreeBSD.ORG Subject: Re: re-reading /etc/fstab ... In-Reply-To: <20000417.23514600@bartequi.ottodomain.org> Date: Tue, 18 Apr 2000 00:05:14 -0600 From: Chris Fedde Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Mon, 17 Apr 2000 23:51:46 GMT Salvo Bartolotta wrote: +------------------ | Dear FreeBSDers, | | yet another question :-) | | If I turn on e.g. the "noatime" option on a ufs filesystem (eg "/" or | "/usr"), and I want to have my /etc/fstab re-read, I seem to | understand that I have to reboot. | | Alternatively, If I do NOT wish to reboot, I should issue a "shutdown" | command (with no options whatsoever), unmount the filesystem(s), and | remount them. | | The problems arise with the "/" filesystem. Incidentally, "mount -u /" | might damage it. In particular, I seem to understand that switching | from read only to read/write is harmless; whereas switching from | read/write to read only may actually damage the FS -- especially if | this happens a few times. | | Is there a safe way to turn the option on without rebooting in such | cases ? Am I (yawn) missing anything trivial ? | | Many, many thanks for your help (and patience !) | | Best regards, | Salvo +------------------ Taking a file system from rw to ro while it is active can cause some data to be lost. mount -u protects against causing a problem unless you have the "force" option on. Taking a fs from ro to rw while it is active is not a problem. You can mount and unmount non active file systems to your heart's content and change their options using -u and mount will do its best to prevent a problem. I'd do the experimentation on the command line before committing it in fstab. It is safe to run 'mount -a -u' as long as the changes in /etc/fstab are benign. chris -- Chris Fedde 303 773 9134 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message