overrideable via max_open_files). If this field has been customized
in ceph.conf it should likely be adjusted upwards.
+Upgrading from v0.61 "Cuttlefish"
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+In addition to the above notes about upgrading from v0.66:
+
+* There has been a huge revamp of the 'ceph' command-line interface
+ implementation. The ``ceph-common`` client library needs to be
+ upgrade before ``ceph-mon`` is restarted in order to avoid problems
+ using the CLI (the old ``ceph`` client utility cannot talk to the
+ new ``ceph-mon``).
+
+* The CLI is now very careful about sending the 'status' one-liner
+ output to stderr and command output to stdout. Scripts relying on
+ output should take care.
+
+* The 'ceph osd tell ...' and 'ceph mon tell ...' commands are no
+ longer supported. Any callers should use::
+
+ ceph tell osd.<id or *> ...
+ ceph tell mon.<id or name or *> ...
+
+ The 'ceph mds tell ...' command is still there, but will soon also
+ transition to 'ceph tell mds.<id or name or *> ...'
+
+* The 'ceph osd crush add ...' command used to take one of two forms::
+
+ ceph osd crush add 123 osd.123 <weight> <location ...>
+ ceph osd crush add osd.123 <weight> <location ...>
+
+ This is because the id and crush name are redundant. Now only the
+ simple form is supported, where the osd name/id can either be a bare
+ id (integer) or name (osd.<id>)::
+
+ ceph osd crush add osd.123 <weight> <location ...>
+ ceph osd crush add 123 <weight> <location ...>
+
+* There is now a maximum RADOS object size, configurable via 'osd max
+ object size', defaulting to 100 GB. Note that this has no effect on
+ RBD, CephFS, or radosgw, which all stripe over objects. If you are
+ using librados and storing objects larger than that, you will need
+ to adjust 'osd max object size', and should consider using smaller
+ objects instead.
+
+* The 'osd min down {reporters|reports}' config options have been
+ renamed to 'mon osd min down {reporters|reports}', and the
+ documentation has been updated to reflect that these options apply
+ to the monitors (who process failure reports) and not OSDs. If you
+ have adjusted these settings, please update your ``ceph.conf''
+ accordingly.
+
Notable changes since v0.66
~~~~~~~~~~~~~~~~~~~~~~~~~~~