proc-sys-fs-binfmt_misc.automount failed service

Question

I am using ubuntu 14.10.

I have just installed systemd and I have a failing service, proc-sys-fs-binfmt_misc.automount.

I've seen here it's a part of systemd:

Is this file important? How do I solve the activation issue ?

The output of systemctl status:

svassaux@vps127101:~$ systemctl status
proc-sys-fs-binfmt_misc.automount -> '/org/freedesktop/systemd1/unit/proc_2dsys_2dfs_2dbinfmt_5fmisc_2eautomount'
proc-sys-fs-binfmt_misc.automount - Arbitrary Executable File Formats File System Automount Point
   Loaded: loaded (/lib/systemd/system/proc-sys-fs-binfmt_misc.automount; static)
   Active: failed (Result: resources)
    Where: /proc/sys/fs/binfmt_misc
     Docs: https://www.kernel.org/doc/Documentation/binfmt_misc.txt
           http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems

EDIT: my unit file:

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.

[Unit]
Description=Arbitrary Executable File Formats File System Automount Point
Documentation=https://www.kernel.org/doc/Documentation/binfmt_misc.txt
Documentation=http://www.freedesktop.org/wiki/Software/systemd/APIFileSystems
DefaultDependencies=no
Before=sysinit.target
ConditionPathExists=/proc/sys/fs/binfmt_misc/
ConditionPathIsReadWrite=/proc/sys/

[Automount]
Where=/proc/sys/fs/binfmt_misc

Solution

The binfmt_misc mechanism is used to register handlers for "exotic" binary format to enable the kernel to execute such files directly. Just as plain ELF binaries are executed using /lib*/ld-linux*.so.2 and various scripts are executed by whatever is on their first "shebang" line, any other file format can be made executable by telling the kernel how to recognize the format and what to run. Probably the most common user of the binfmt_misc mechanism is WINE, which needs it to enable running Windows executables using "./program.exe".

Thus, unless you're using this feature of WINE feature, I'd guess your system will work normally even with a nonfunctional binfmt_misc mechanism.

As for why activating the automount unit failed on your system, that's impossible to tell without inspecting system logs (at least). Automount units are very lightweight and thus quite unlikely to fail. I'd guess that your problem may be related to some non-standard security or resource-limit settings on your system.

You can take a closer look at the failing unit using journalctl _SYSTEMD_UNIT=proc-sys-fs-binfmt_misc.automount. If that does not help, try journalctl -b, find the point where the unit failed to start and look around for any errors that could be related.

Comments

[dawud]

Please include in your question the contents of the unit and specify what operating system you are using.

[Sébastien]

hello! thanks, you will find those info in my edits.

[rubo77]

You can disable it with systemctl disable proc-sys-fs-binfmt_misc.automount