From 3e8305efe091411395123eab35ef2a58ac88140b Mon Sep 17 00:00:00 2001 From: Rishabh Dave Date: Sun, 28 Jul 2024 22:58:49 +0530 Subject: [PATCH] doc/cephfs: add doc for disabling mgr/volumes plugin Signed-off-by: Rishabh Dave (cherry picked from commit 373910de34fc9e1d98218aed0361cd9bf3badffa) --- doc/cephfs/fs-volumes.rst | 23 +++++++++++++++++++++++ doc/cephfs/troubleshooting.rst | 5 +++++ 2 files changed, 28 insertions(+) diff --git a/doc/cephfs/fs-volumes.rst b/doc/cephfs/fs-volumes.rst index 5f9405bb864e9..3670f454e6007 100644 --- a/doc/cephfs/fs-volumes.rst +++ b/doc/cephfs/fs-volumes.rst @@ -888,5 +888,28 @@ group. This will cause every subvolume within the group to be automatically pinned to one of the available ranks on the file system. + +.. _disabling-volumes-plugin: + +Disabling Volumes Plugin +------------------------ +By default the volumes plugin is enabled and set to ``always on``. However, in +certain cases it might be appropriate to disable it. For example, when a CephFS +is in a degraded state, the volumes plugin commands may accumulate in MGR +instead of getting served. Which eventually causes policy throttles to kick in +and the MGR becomes unresponsive. + +In this event, volumes plugin can be disabled even though it is an +``always on`` module in MGR. To do so, run ``ceph mgr module disable volumes +--yes-i-really-mean-it``. Do note that this command will disable operations +and remove commands of volumes plugin since it will disable all CephFS +services on the Ceph cluster accessed through this plugin. + +Before resorting to a measure as drastic as this, it is a good idea to try less +drastic measures and then assess if the file system experience has improved due +to it. One example of such less drastic measure is to disable asynchronous +threads launched by volumes plugins for cloning and purging trash. + + .. _manila: https://github.com/openstack/manila .. _CSI: https://github.com/ceph/ceph-csi diff --git a/doc/cephfs/troubleshooting.rst b/doc/cephfs/troubleshooting.rst index 0e511526b96c0..62dd3561c47d6 100644 --- a/doc/cephfs/troubleshooting.rst +++ b/doc/cephfs/troubleshooting.rst @@ -407,6 +407,11 @@ its associated key. A less drastic but half-fix is to change the osd cap for your user to just ``caps osd = "allow rw"`` and delete ``tag cephfs data=....`` +Disabling Volumes Plugin +======================== +In certain scenarios, volumes plugin might be needed to disabled to prevent compromise +for rest of the Ceph cluster. For details see: :ref:`disabling-volumes-plugin` + Reporting Issues ================ -- 2.39.5