doc: clarify MDS failed state

Since 58eaa237b0a1, an MDS is only promoted if it is compatible with the
file system compat. The users may see persistent failed state even they
have enough standby daemons.

Signed-off-by: 胡玮文 <huww98@outlook.com>

diff --git a/doc/cephfs/mds-states.rst b/doc/cephfs/mds-states.rst
index 7598f49487ca0aa6d256f842c33fec6baced0a99..b221396d6b69bae6b4d24bd72c2c88982a14bf56 100644 (file)
--- a/doc/cephfs/mds-states.rst
+++ b/doc/cephfs/mds-states.rst
@@ -154,7 +154,10 @@ No MDS actually holds this state. Instead, it is applied to the rank in the file
     failed  0
     ...
 
-Rank 0 is part of the failed set.
+Rank 0 is part of the failed set and is pending to be taken over by a standby
+MDS. If this state persists, it indicates no suitable MDS daemons found to be
+assigned to this rank. This may be caused by not enough standby daemons, or all
+standby daemons have incompatible campat (see also :ref:`upgrade-mds-cluster`).
 
 
 ::

diff --git a/doc/cephfs/upgrading.rst b/doc/cephfs/upgrading.rst
index 2dc29e1298bb1fc5c7815f5f09bacb63ab8e51b6..c06e3e8e0ca2f112684d8840f6d136f8fa9c06f0 100644 (file)
--- a/doc/cephfs/upgrading.rst
+++ b/doc/cephfs/upgrading.rst
@@ -1,3 +1,5 @@
+.. _upgrade-mds-cluster:
+
 Upgrading the MDS Cluster
 =========================