diff --git a/doc/config-cluster/ceph-conf.rst b/doc/config-cluster/ceph-conf.rst index 8d8af483a25..abae6f41004 100644 --- a/doc/config-cluster/ceph-conf.rst +++ b/doc/config-cluster/ceph-conf.rst @@ -363,3 +363,24 @@ Example ceph.conf .. literalinclude:: demo-ceph.conf :language: ini +Runtime Configuration +===================== + +Ceph allows you to make changes to the configuration of an ``ceph-osd``, +``ceph-mon``, or ``ceph-mds`` daemon at runtime. This capability is quite +useful for increasing/decreasing logging output, enabling/disabling debug +settings, and even for runtime optimization. The following reflects runtime +configuration usage:: + + ceph {daemon-type} tell {id or *} injectargs --{name} {value} [--{name} {value}] + +Replace ``{daemon-type}`` with one of ``osd``, ``mon`` or ``mds``. You may apply +the runtime setting to all daemons of a particular type with ``*``, or specify +a specific daemon's ID (i.e., its number or letter). For example, to increase +debug logging for a ``ceph-osd`` daemon named ``osd.0``, execute the following:: + + ceph osd tell 0 injectargs --debug_osd 20 + +In your ``ceph.conf`` file, you may use spaces when specifying a setting name. +When specifying a setting name on the command line, ensure that you use an +underscore (``_``) between terms (e.g., ``debug osd`` becomes ``debug_osd``). \ No newline at end of file