unmounting a filesystem safely that doesn't exist anymore

[Zaphod Beeblebrox]

On 6/12/06, Ulrich Spoerlein <uspoerlein at gmail.com> wrote:
>
> Björn König wrote:
>


> > I did a mistake: I unplugged my digital camera accidentally before I
> unmounted the
> > filesystem. *doh* This happens very often, because I'm very
> scatterbrained. =) The kernel
> > will panic and all filesystems remain unclean in any case now. I know
> that this is a well
> > know issue and in past discussions you stated that this behaviour is
> intended and won't be
> > changed ad hoc. I just want to know if somebody knows a workaround or
> small trick that
> > prevents the other filesystems from being unclean on next boot-up.
>
> You might give the automounter (am-utils) a whirl. They are very
> confusing to set up, but you can set the unmount-if-unused timeout to
> something like 5 seconds. This could narrow the window enough to not
> panic you system frequently :)


That's rather hackish ... especially since this is a common problem and a
rather obvious hole in using FreeBSD for noobs.

It seems that a better solution would be to allow filesystems to be mounted
with a 'sync' flag.  Or even an ULTRA-sync flag.  Meaning strict sync
semantics and even 'sync' running against the FS every few seconds.  If a
filesystem so-mounted completely disappears (or errors out), then it should
just go "poof" as if it was umount -f'd.