Merge pull request #16611 from liewegas/wip-doc-health

doc/rados/operations/health-checks: osd section

Reviewed-by: Josh Durgin <jdurgin@redhat.com>
Reviewed-by: Kefu Chai <kchai@redhat.com>
Reviewed-by: John Spray <john.spray@redhat.com>
Reviewed-by: xie xingguo <xie.xingguo@zte.com.cn>

diff --cc doc/rados/operations/health-checks.rst
index 6329a5b9ecfe1fe79e3ed65cb55ab332f040ae12,b612995081e6dcaf3ba7f0a054571132dcab60da..68106352e1749e522c6e7f9e67ccf57c2e6a34e1
--- 1/doc/rados/operations/health-checks.rst
--- 2/doc/rados/operations/health-checks.rst
+++ b/doc/rados/operations/health-checks.rst
@@@ -28,9 -28,16 +28,16 @@@ OSD
  OSD_DOWN
  ________
  
- One or more OSDs are marked down
+ One or more OSDs are marked down.  The ceph-osd daemon may have been
+ stopped, or peer OSDs may be unable to reach the OSD over the network.
+ Common causes include a stopped or crashed daemon, a down host, or a
+ network outage.
+ 
+ Verify the host is healthy, the daemon is started, and network is
+ functioning.  If the daemon has crashed, the daemon log file
+ (``/var/log/ceph/ceph-osd.*``) may contain debugging information.
  
 -OSD_<crush type>_DOWN 
 +OSD_<crush type>_DOWN
  _____________________
  
  (e.g. OSD_HOST_DOWN, OSD_ROOT_DOWN)
@@@ -127,25 -372,19 +372,37 @@@ triggering the data migration, with:
  MANY_OBJECTS_PER_PG
  ___________________
  
+ One or more pools has an average number of objects per PG that is
+ significantly higher than the overall cluster average.  The specific
+ threshold is controlled by the ``mon_pg_warn_max_object_skew``
+ configuration value.
+ 
+ This is usually an indication that the pool(s) containing most of the
+ data in the cluster have too few PGs, and/or that other pools that do
+ not contain as much data have too many PGs.  See the discussion of
+ *TOO_MANY_PGS* above.
+ 
+ The threshold can be raised to silence the health warning by adjusting
+ the ``mon_pg_warn_max_object_skew`` config option on the monitors.
  
 +POOL_APP_NOT_ENABLED
 +____________________
 +
 +A pool exists that contains one or more objects but has not been
 +tagged for use by a particular application.
 +
 +Resolve this warning by labeling the pool for use by an application.  For
 +example, if the pool is used by RBD,::
 +
 +  rbd pool init <poolname>
 +
 +If the pool is being used by a custom application 'foo', you can also label
 +via the low-level command::
 +
 +  ceph osd pool application enable foo
 +
 +For more information, see :doc:`pools.rst#associate-pool-to-application`.
 +
  POOL_FULL
  _________
  

diff --cc src/mon/PGMap.cc
Simple merge