In-memory Log Dump
==================
-In-memory logs can be dumped by setting ``mds_extraordinary_events_dump_interval``
-during a lower level debugging (log level < 10). ``mds_extraordinary_events_dump_interval``
-is the interval in seconds for dumping the recent in-memory logs when there is an Extra-Ordinary event.
+In-memory logs can be dumped by setting
+``mds_extraordinary_events_dump_interval`` when
+the log level is set to less than ``10``.
+``mds_extraordinary_events_dump_interval`` is the interval in seconds for
+dumping the recent in-memory logs when there is an extraordinary event.
-The Extra-Ordinary events are classified as:
+Extraordinary events include the following:
* Client Eviction
* Missed Beacon ACK from the monitors
* Missed Internal Heartbeats
-In-memory Log Dump is disabled by default to prevent log file bloat in a production environment.
-The below commands consecutively enables it::
+In-memory log dump is disabled by default. This prevents production
+environments from experiencing log file bloat by default.
- $ ceph config set mds debug_mds <log_level>/<gather_level>
- $ ceph config set mds mds_extraordinary_events_dump_interval <seconds>
+Run the following two commands in order to enable in-memory log dumping:
-The ``log_level`` should be < 10 and ``gather_level`` should be >= 10 to enable in-memory log dump.
-When it is enabled, the MDS checks for the extra-ordinary events every
-``mds_extraordinary_events_dump_interval`` seconds and if any of them occurs, MDS dumps the
-in-memory logs containing the relevant event details in ceph-mds log.
+#.
+ .. prompt:: bash $
-.. note:: For higher log levels (log_level >= 10) there is no reason to dump the In-memory Logs and a
- lower gather level (gather_level < 10) is insufficient to gather In-memory Logs. Thus a
- log level >=10 or a gather level < 10 in debug_mds would prevent enabling the In-memory Log Dump.
- In such cases, when there is a failure it's required to reset the value of
- mds_extraordinary_events_dump_interval to 0 before enabling using the above commands.
+ ceph config set mds debug_mds <log_level>/<gather_level>
+ Set ``log_level`` to a value of less than ``10``. Set ``gather_level`` to a
+ value greater than ``10``. When those two values have been set, in-memory
+ log dump is enabled.
+#.
+ .. prompt:: bash #
+
+ ceph config set mds mds_extraordinary_events_dump_interval <seconds>
+ When in-memory log dumping is enabled, the MDS checks for
+ extraordinary events every ``mds_extraordinary_events_dump_interval``
+ seconds. If any extraordinary event occurs, the MDS dumps the in-memory logs
+ that contain relevant event details to the Ceph MDS log.
+
+.. note:: When higher log levels are set (``log_level`` greater than or equal
+ to ``10``) there is no reason to dump the in-memory logs. A lower gather
+ level (``gather_level`` less than ``10``) is insufficient to gather in-
+ memory logs. This means that a log level of greater than or equal to ``10``
+ or a gather level of less than ``10`` in ``debug_mds`` prevents enabling
+ in-memory-log dumping. In such cases, if there is a failure, you must reset
+ the value of ``mds_extraordinary_events_dump_interval`` to ``0`` before
+ enabling the use of the above commands.
-The In-memory Log Dump can be disabled using::
+Disable in-memory log dumping by running the following command:
+
+.. prompt:: bash #
- $ ceph config set mds mds_extraordinary_events_dump_interval 0
+ ceph config set mds mds_extraordinary_events_dump_interval 0
Filesystems Become Inaccessible After an Upgrade
================================================