On Mon, Jun 3, 2019 at 1:24 PM Gregory Farnum <gfarnum@xxxxxxxxxx> wrote: > > On Mon, Jun 3, 2019 at 1:07 PM Ilya Dryomov <idryomov@xxxxxxxxx> wrote: > > Can we also discuss how useful is allowing to recover a mount after it > > has been blacklisted? After we fail everything with EIO and throw out > > all dirty state, how many applications would continue working without > > some kind of restart? And if you are restarting your application, why > > not get a new mount? > > > > IOW what is the use case for introducing a new debugfs knob that isn't > > that much different from umount+mount? > > People don't like it when their filesystem refuses to umount, which is > what happens when the kernel client can't reconnect to the MDS right > now. I'm not sure there's a practical way to deal with that besides > some kind of computer admin intervention. Furthermore, there are often many applications using the mount (even with containers) and it's not a sustainable position that any network/client/cephfs hiccup requires a remount. Also, an application that fails because of EIO is easy to deal with a layer above but a remount usually requires grump admin intervention. -- Patrick Donnelly, Ph.D. He / Him / His Senior Software Engineer Red Hat Sunnyvale, CA GPG: 19F28A586F808C2402351B93C3301A3E258DD79D