Debugging Failed Startup

Does anyone have a hint on how I'd go about debugging why PostgreSQL 11 is
not starting on CentOS 7?
Was running fine for several weeks then fails to come up after a reboot.

I did change the name of the CentOS7 server, but I don't expect that to
have any effect on the database.

I'm running debug5 to the logs.

There's nothing in the ./log directory past the database shutting down.
Here's what's in messages. All seems to be fine and then boom!

... postmaster: LOG: listening on IPv6 address "::1", port 5432
... postmaster: LOG: listening on IPv4 address "127.0.0.1", port 5432
... postmaster: LOG: listening on Unix socket
"/var/run/postgresql/.s.PGSQL.5432"
... postmaster: LOG: listening on Unix socket "/tmp/.s.PGSQL.5432"
... postmaster: DEBUG: invoking IpcMemoryCreate(size=148553728)
... postmaster: DEBUG: SlruScanDirectory invoking callback on
pg_notify/0000
... postmaster: DEBUG: removing file "pg_notify/0000"
... postmaster: DEBUG: dynamic shared memory system will support 288
segments
... postmaster: DEBUG: created dynamic shared memory control segment
1998722972 (6928 bytes)
... postmaster: DEBUG: max_safe_fds = 983, usable_fds = 1000, already_open
= 7
... postmaster: LOG: redirecting log output to logging collector process
... postmaster: HINT: Future log output will appear in directory "log".
... systemd: postgresql-11.service: main process exited, code=exited,
status=1/FAILURE
... systemd: Failed to start PostgreSQL 11 database server.
... systemd: Unit postgresql-11.service entered failed state.

--Ray