From: sct@dcs.ed.ac.uk (Stephen Tweedie) Subject: Re: Help: EXT2-fs Date: Tue, 21 Sep 1993 19:04:50 GMT
Hi,
In article <1993Sep20.145052.20513@aber.ac.uk>, pcg@aber.ac.uk (Piercarlo Antonio Grandi) writes:
> On 16 Sep 1993 06:39:47 GMT, Heon J. Jo (hjj101@cac.psu.edu) wrote:
> EXT2-fs warning: mounting unchecked file system, running e2fsck is
> recommended
> To prevent this the root filesystem must be mounted RO at boot,
> fsck'ed and then remounted RW, and then it must be remounted RO just
> before shutdown, which is achieved by unmounting it.
> The only thing I am a bit unsure about is whether one needs to
> reboot in case fsck had to repair the root; IMNHO I think this is
> not necessary, remounting *ought* to reload the updated filesystem
> information.
Nope! You *do* need to reboot in order to be completely safe. The
trouble is that you can't completely unmount the root filesystem; if
you try to do so, the filesystem still hangs around afterwards in a
read-only state. So, you can't flush out any inode information that
the kernel may have cached about the filesystem.
Because of this danger that the kernel may have cached out-of-date
filesystem information, it is dangerous to let the kernel write to the
root filesystem after it has been fixed by fsck. That's why a reboot
is necessary in such a situation. However, there should be no harm in
continuing the boot process if it was a filesystem other than root
which was repaired.
Cheers,
Stephen.