From 2d28faaeea11988867471a53e40145f309951307 Mon Sep 17 00:00:00 2001 From: Rishabh Dave Date: Tue, 27 Aug 2024 13:33:23 +0530 Subject: [PATCH] doc/cephfs: update about changing max_mds FS setting variable Update the documentation for CephFs admininstration as well troubleshooting. Signed-off-by: Rishabh Dave --- doc/cephfs/administration.rst | 11 +++++++++-- doc/cephfs/troubleshooting.rst | 5 +++++ 2 files changed, 14 insertions(+), 2 deletions(-) diff --git a/doc/cephfs/administration.rst b/doc/cephfs/administration.rst index 5760e67f73e..07646bff067 100644 --- a/doc/cephfs/administration.rst +++ b/doc/cephfs/administration.rst @@ -61,10 +61,17 @@ is a subset of the same information from the ``ceph fs dump`` command. :: - ceph fs set + ceph fs set [--yes-i-really-mean-it] Change a setting on a file system. These settings are specific to the named -file system and do not affect other file systems. +file system and do not affect other file systems. Confirmation flag is only +needed for changing ``max_mds`` when cluster is unhealthy. + +.. note:: It is mandatory to pass confirmation flag (--yes--i-really-mean-it) + for modifying FS setting variable ``max_mds`` when cluster is unhealthy. + It has been added a precaution to tell users that modifying ``max_mds`` + during troubleshooting or recovery might not help. Instead, it might + further destabilize the cluster. :: diff --git a/doc/cephfs/troubleshooting.rst b/doc/cephfs/troubleshooting.rst index 34de1b7501d..78d0a8f54d3 100644 --- a/doc/cephfs/troubleshooting.rst +++ b/doc/cephfs/troubleshooting.rst @@ -128,6 +128,11 @@ things to do: That prevents any clients from establishing new sessions with the MDS. +* **Dont tweak max_mds** Modifying the FS setting variable ``max_mds`` is + sometimes perceived as a good step during troubleshooting or recovery effort. + Instead, doing so might further destabilize the cluster. If ``max_mds`` must + be changed in such circumstances, run the command to change ``max_mds`` with + the confirmation flag (``--yes-i-really-mean-it``) Expediting MDS journal trim -- 2.39.5