Date: Thu, 10 Mar 2005 13:45:00 -0500 From: Erez Zadok <ezk@cs.sunysb.edu> To: Lou Kamenov <loukamenov@gmail.com> Cc: Jeremie Le Hen <jeremie@le-hen.org> Subject: Re: the current status of nullfs, unionfs Message-ID: <200503101845.j2AIj0LB008584@agora.fsl.cs.sunysb.edu> In-Reply-To: Your message of "Thu, 10 Mar 2005 12:24:17 EST." <76f962c6050310092461fc850@mail.gmail.com>
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In message <76f962c6050310092461fc850@mail.gmail.com>, Lou Kamenov writes: > On Thu, 10 Mar 2005 09:19:10 -0500, Michael W. Lucas > <mwlucas@blackhelicopters.org> wrote: > > On Thu, Mar 10, 2005 at 12:38:43PM +0100, Jeremie Le Hen wrote: > > But the mere existence of even a basic regression test would be a > > start and would encourage people to not hose things further. > [..] > > Folks, don't let the fact that you're not a guru stop you from taking > > a kiddie step and submitting a basic test! > [..] > > I do use unionfs on daily basis. Mostly to union $home/bin directories and > such. For the last 1.5y I had it crash only 2 times. Of course trying > to unmount /bin > will turn into hell. I've used it successfully with pdumpfs from ports > to restore > old filespace view. I surely think that a stable unionfs will be a > good thing (tm). > > Erez's unionfs has the same problem, the case there is that you wont be > able to unmount it at all. (At least last time I tried with 1.0.3) You should NEVER be allowed to unmount an underlying file system of a stackable file system, if it's busy or in use, no more than you can remove a /dev/sda drive while ffs is mounted on it. Our approach in the Linux unionfs is to prevent users from shooting themselves too much in the foot. :-) However, our unionfs does provide mechanisms such that read-only or non-busy file system branches in the union, *can* indeed be removed safely. Generally we can support arbitrary insertions and removals of branches anywhere in the (fan-out) union; however, we found out that most of our unionfs users rarely want or need that. BTW, the latest version of our linux unionfs is 1.0.9. There has been a lot of work done on our unionfs recently, and it was deemed stable enough that several LiveCD distros, including the just-released Knoppix 3.8, are using it. > Problem or not it could be easily solved with simple heuristics. > Building a filespace > with unioning shouldnt really be that hard. > > best, > l > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" > Erez.
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