From owner-freebsd-hackers Wed Sep 8 11:12: 3 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from apollo.backplane.com (apollo.backplane.com [209.157.86.2]) by hub.freebsd.org (Postfix) with ESMTP id F111C14FFB; Wed, 8 Sep 1999 11:12:00 -0700 (PDT) (envelope-from dillon@apollo.backplane.com) Received: (from dillon@localhost) by apollo.backplane.com (8.9.3/8.9.1) id LAA88623; Wed, 8 Sep 1999 11:11:12 -0700 (PDT) (envelope-from dillon) Date: Wed, 8 Sep 1999 11:11:12 -0700 (PDT) From: Matthew Dillon Message-Id: <199909081811.LAA88623@apollo.backplane.com> To: David Scheidt Cc: Zhihui Zhang , Luoqi Chen , freebsd-fs@FreeBSD.ORG, freebsd-hackers@FreeBSD.ORG Subject: Re: The usage of MNT_RELOAD References: Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG :> Does fsck have to run on a MOUNTED filesystem? If so, your answer makes :> sense to me: if fsck modifies the on-disk copy of the superblock, it does :> not have to unmount and then remount the filesystem, it only need to :> reload the superlock for disk. : :The root filesystem is mounted when it is fscked, as it is difficult to run :fsck, which lives on the root filesystem, without mounting the root :filesystem. You shouldn't run fsck on a mounted filesystem, except for :this. The results are generally not fun. : :David Scheidt The root filesystem is mounted *READ-ONLY* initially. fsck is then run on all filesystems. Once fsck is done the root filesystem is remounted R/W and the remaining filesystems are mounted R/W. It's relatively safe to run fsck on a filesytem which has been mounted read-only. It is not safe to run fsck on a filesystem which has been mounted R/W. It is best, of course, to run fsck only on filesystems that have not been mounted but this cannot be done for the root filesystem for obvious reasons, hence the read-only mount + fsck + remount R/W. -Matt Matthew Dillon To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message