A systemd bug fix has been released for Debian GNU/Linux 8 Extended LTS to address an issue where remounting a network filesystem read-only can hang.

ELA-530-1 systemd bug fix

Package systemd
Version 215-17+deb8u14

systemd-shutdown is run after the network is stopped, so remounting a network filesystem read-only can hang. A simple umount is the most useful thing that can be done for a network filesystem once the network is down.

For Debian 8 jessie, these problems have been fixed in version 215-17+deb8u14.

We recommend that you upgrade your systemd packages.

Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/

  ELA-530-1 systemd bug fix