v0.74
~~~~~

- We now default to the 'bobtail' CRUSH tunable values that are first supported
  by Ceph clients in bobtail (v0.48) and Linux kernel version v3.9.  If you
  plan to access a newly created Ceph cluster with an older kernel client, you
  should use 'ceph osd crush tunables legacy' to switch back to the legacy
  behavior.  Note that making that change will likely result in some data
  movement in the system, so adjust the setting before populating the new
  cluster with data.

- We now set the HASHPSPOOL flag on newly created pools (and new
  clusters) by default.  Support for this flag first appeared in
  v0.64; v0.67 Dumpling is the first major release that supports it.
  It is first supported by the Linux kernel version v3.9.  If you plan
  to access a newly created Ceph cluster with an older kernel or
  clients (e.g, librados, librbd) from a pre-dumpling Ceph release,
  you should add 'osd pool default flag hashpspool = false' to the
  '[global]' section of your 'ceph.conf' prior to creating your
  monitors (e.g., after 'ceph-deploy new' but before 'ceph-deploy mon
  create ...').


v0.72.2
~~~~~~~
- As part of fix for #6796, 'ceph osd pool set <pool> <var> <arg>' now
  receives <arg> as an integer instead of a string.  This affects how
  'hashpspool' flag is set/unset: instead of 'true' or 'false', it now
  must be '0' or '1'.