On Thu, Nov 26, 2020 at 11:25:40 +0100, Stefan G. Weichinger wrote: > Am 25.11.20 um 20:57 schrieb Nathan Stratton Treadway: > >On Wed, Nov 25, 2020 at 14:34:17 -0500, Nathan Stratton Treadway wrote: > >>Also, do you see the same defunct pigz process that Jason reported in > >>his original post? > > > >Am 30.05.18 um 20:21 schrieb Jason L Tibbitts III: > >>root 2690 9.1 0.0 317692 11020 pts/0 S+ 12:38 1:43 | > >> \_ amrecover math -s backup2 -t backup2 > >>root 2996 32.5 0.0 0 0 pts/0 Z+ 12:48 2:52 | > >> \_ [pigz] <defunct> > >>root 2998 3.3 0.0 0 0 pts/0 Z+ 12:48 0:17 | > >> \_ [xfsrestore] <defunct> > > > >Assuming you are seeing this same behavior: one theory that comes to > >mind is that pigz could be spawning subprocesses which then somehow > >confuse amrecover such that it doesn't properly detect when pigz > >terminates (and just keeps waiting for that to happen, even though it > >already has happened). > > > >I don't know enough about how amrecover spawn the pipes to know how > >likely that is, but one thing you could try is to kill the amrecover > >process with a SIGCHLD signal (once it reaches the above "everything is > >hung" situation) and see if one or both of those defunct processes go > >away, and if the amrecover process starts doing work again > >afterwards.... > > Not sure how to show the process tree as shown above ...
(I think Jason's output was generated using the "--forest" option to ps, but really all that matters is the "Z" process state for the two subprocesses). > > "kill -s SIGCHLD" .. ran it against the PIDs of amrecover and pigz, > no effect. > > pigz isn't even killed by a "-9" > The fact that the pigz process is in defunct/"Z"ombie status means it's already dead and only still exists in the process listing because the parent process hasn't read the exit code yet. So even a -9 won't help (since that process is already dead). I was hoping SIGCHLD on the amrecover process would trick it into exiting whatever wait-loop it is in and checking for subprocesses that have already terminated (both pigz and xfsrestore in the above listing)... but sounds like that didn't work. Nathan ---------------------------------------------------------------------------- Nathan Stratton Treadway - natha...@ontko.com - Mid-Atlantic region Ray Ontko & Co. - Software consulting services - http://www.ontko.com/ GPG Key: http://www.ontko.com/~nathanst/gpg_key.txt ID: 1023D/ECFB6239 Key fingerprint = 6AD8 485E 20B9 5C71 231C 0C32 15F3 ADCD ECFB 6239