From d536ec3b7ab04267992367d3dcf81ba7b4940d7f Mon Sep 17 00:00:00 2001 From: Zac Dover Date: Thu, 14 Aug 2025 15:20:53 +1000 Subject: [PATCH] doc/cephfs: edit troubleshooting.rst Edit the section "In-memory log dumps" in doc/cephfs/troubleshooting.rst. Signed-off-by: Zac Dover (cherry picked from commit bc1aa66f356981ed977ac96e7d235f4f9c43547b) fixup Co-authored-by: Anthony D'Atri Signed-off-by: Zac Dover (cherry picked from commit 3d8a6759c45a91c27d8698c0d0033638d06279f7) --- doc/cephfs/troubleshooting.rst | 55 ++++++++++++++++++++++------------ 1 file changed, 36 insertions(+), 19 deletions(-) diff --git a/doc/cephfs/troubleshooting.rst b/doc/cephfs/troubleshooting.rst index bf895f3c18e..a5e2e72c812 100644 --- a/doc/cephfs/troubleshooting.rst +++ b/doc/cephfs/troubleshooting.rst @@ -455,36 +455,53 @@ To disable debug logging, run a command of the following form: 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 / - $ ceph config set mds mds_extraordinary_events_dump_interval +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 / + 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 + 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 ================================================ -- 2.39.5