Why vdsmd is failing to start with systemd error "start-pre operation timed out. Terminating"

Issue

• vdsmd fails to start and timed out after default systemd time out of 90 seconds.
• System log shows below messages.

May 29 07:28:40  systemd: Starting Virtual Desktop Server Manager...
May 29 07:28:40  vdsmd_init_common.sh: vdsm: Running mkdirs
May 29 07:28:40  vdsmd_init_common.sh: vdsm: Running configure_coredump
May 29 07:28:40  vdsmd_init_common.sh: vdsm: Running configure_vdsm_logs
May 29 07:28:40  vdsmd_init_common.sh: vdsm: Running wait_for_network
May 29 07:28:41  vdsmd_init_common.sh: vdsm: Running run_init_hooks
May 29 07:28:48  vdsmd_init_common.sh: vdsm: Running upgraded_version_check
May 29 07:28:48  vdsmd_init_common.sh: vdsm: Running check_is_configured
May 29 07:29:06  vdsmd_init_common.sh: Current revision of multipath.conf detected, preserving
May 29 07:29:06  vdsmd_init_common.sh: libvirt is already configured for vdsm
May 29 07:29:07  vdsmd_init_common.sh: vdsm: Running validate_configuration
May 29 07:29:23  vdsmd_init_common.sh: SUCCESS: ssl configured to true. No conflicts
May 29 07:29:23  vdsmd_init_common.sh: vdsm: Running prepare_transient_repository
May 29 07:29:56  vdsmd_init_common.sh: vdsm: Running syslog_available
May 29 07:29:56  vdsmd_init_common.sh: vdsm: Running nwfilter

May 29 07:30:11  systemd: vdsmd.service start-pre operation timed out. Terminating.