Ceph daemon logs
================
-Logging to stdout
------------------
+Logging to journald
+-------------------
-Ceph daemons traditionally write logs to ``/var/log/ceph``. Ceph
-daemons log to stderr by default and Ceph logs are captured by the
-container runtime environment. By default, most systems send these
-logs to journald, which means that they are accessible via
-``journalctl``.
+Ceph daemons traditionally write logs to ``/var/log/ceph``. Ceph daemons log to
+journald by default and Ceph logs are captured by the container runtime
+environment. They are accessible via ``journalctl``.
-Example of logging to stdout
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+.. note:: Prior to Quincy, ceph daemons logged to stderr.
+
+Example of logging to journald
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For example, to view the logs for the daemon ``mon.foo`` for a cluster
with ID ``5c5a50ae-272a-455d-99e9-32c6a013e694``, the command would be
----------------
You can also configure Ceph daemons to log to files instead of to
-stderr if you prefer logs to appear in files (as they did in earlier,
+journald if you prefer logs to appear in files (as they did in earlier,
pre-cephadm, pre-Octopus versions of Ceph). When Ceph logs to files,
the logs appear in ``/var/log/ceph/<cluster-fsid>``. If you choose to
-configure Ceph to log to files instead of to stderr, remember to
-configure Ceph so that it will not log to stderr (the commands for
+configure Ceph to log to files instead of to journald, remember to
+configure Ceph so that it will not log to journald (the commands for
this are covered below).
Enabling logging to files
ceph config set global log_to_file true
ceph config set global mon_cluster_log_to_file true
-Disabling logging to stderr
-~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Disabling logging to journald
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-If you choose to log to files, we recommend disabling logging to stderr or else
+If you choose to log to files, we recommend disabling logging to journald or else
everything will be logged twice. Run the following commands to disable logging
to stderr:
ceph config set global log_to_stderr false
ceph config set global mon_cluster_log_to_stderr false
+ ceph config set global log_to_journald false
+ ceph config set global mon_cluster_log_to_journald false
+
+.. note:: You can change the default by passing --log-to-file during
+ bootstrapping a new cluster.
Modifying the log retention schedule
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~