[OpenAFS-devel] OpenAFS cache manager cold vs warm shutdown

[Russ Allbery]

Mark Vitale <mvitale@sinenomine.net> writes:

> If afs_shutdown() is called "warm" (afs_cold_shutdown==0), the shutdown
> logic skips the clearing and releasing of some resources.  I see no
> rhyme or reason to which resources AFS leaves unreleased.  Nor do I
> understand the (possibly historical) reason for why there is a
> distinction between cold and warm shutdown.

> For example, on Solaris, umount /afs currently performs a "warm"
> shutdown.  This makes it effectively impossible (catch-22) to perform a
> "cold" shutdown.

> Then there is the question of when it is safe to rmmod/modunload the
> libafs kernel module.  Does warm or cold shutdown affect the answer to
> this question?

My experience on Linux is that cold shutdowns are bad news, and that,
following a cold shutdown, AFS on that system is probably hosed and will
never recover without a reboot.

See, for example:

https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=608173 (RT #128838)
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=732072

-- 
Russ Allbery (eagle@eyrie.org)              <http://www.eyrie.org/~eagle/>