James Pearson wrote:
We are seeing a problem that occurs ~5% of the time when rebooting CentOS 7.7 where systemd gets a 'Connection timed out' to D-Bus just after the D-Bus service starts - from 'journalctl -x' :
... Jan 21 16:09:59 linux7-7.mpc.local systemd[1]: Started D-Bus System Message Bus. -- Subject: Unit dbus.service has finished start-up -- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- Unit dbus.service has finished starting up.
-- The start-up result is done. Jan 21 16:10:24 linux7-7.mpc.local systemd[1]: Failed to register match for Disconnected message: Connection timed out Jan 21 16:10:24 linux7-7.mpc.local systemd[1]: Failed to initialize D-Bus connection: Connection timed out ...
We've managed to work out what the problem is - it is the same issue as given in https://bugzilla.redhat.com/show_bug.cgi?id=1531486
We have a legacy use of NIS for groups - which can cause a boot time deadlock:
systemd->dbus->nis(glibc)->rpcbind->systemd
A workaround is given in https://access.redhat.com/solutions/3900301 (account needed to view) - but it is just essentially reverting the changes made to /usr/lib/systemd/system/rpcbind.socket between 7.5 and 7.6
James Pearson