diff --git a/src/osd/ECBackend.cc b/src/osd/ECBackend.cc
index 810397592d7..9fa036ff7df 100644
--- a/src/osd/ECBackend.cc
+++ b/src/osd/ECBackend.cc
@@ -1121,8 +1121,9 @@ void ECBackend::check_recovery_sources(const OSDMapRef osdmap)
   }
 }
 
-void ECBackend::_on_change(ObjectStore::Transaction *t)
+void ECBackend::on_change()
 {
+  dout(10) << __func__ << dendl;
   writing.clear();
   tid_to_op_map.clear();
   for (map<ceph_tid_t, ReadOp>::iterator i = tid_to_read_map.begin();
diff --git a/src/osd/ECBackend.h b/src/osd/ECBackend.h
index 314e2b07f58..28bcf8a5095 100644
--- a/src/osd/ECBackend.h
+++ b/src/osd/ECBackend.h
@@ -82,7 +82,7 @@ public:
   /// @see ReadOp below
   void check_recovery_sources(const OSDMapRef osdmap);
 
-  void _on_change(ObjectStore::Transaction *t);
+  void on_change();
   void clear_state();
 
   void on_flushed();
diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 8d3813e956f..52a38394bd0 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -426,6 +426,15 @@ void OSDService::pg_stat_queue_dequeue(PG *pg)
   osd->pg_stat_queue_dequeue(pg);
 }
 
+void OSDService::start_shutdown()
+{
+  {
+    Mutex::Locker l(agent_timer_lock);
+    agent_timer.cancel_all_events();
+    agent_timer.shutdown();
+  }
+}
+
 void OSDService::shutdown()
 {
   reserver_finisher.stop();
@@ -446,10 +455,6 @@ void OSDService::shutdown()
     Mutex::Locker l(backfill_request_lock);
     backfill_request_timer.shutdown();
   }
-  {
-    Mutex::Locker l(agent_timer_lock);
-    agent_timer.shutdown();
-  }
   osdmap = OSDMapRef();
   next_osdmap = OSDMapRef();
 }
@@ -1640,6 +1645,8 @@ int OSD::shutdown()
   cct->_conf->set_val("debug_ms", "100");
   cct->_conf->apply_changes(NULL);
 
+  service.start_shutdown();
+
   dispatch_sessions_waiting_on_map();
 
   // Shutdown PGs
diff --git a/src/osd/OSD.h b/src/osd/OSD.h
index 4bc55864701..2ae77e3523f 100644
--- a/src/osd/OSD.h
+++ b/src/osd/OSD.h
@@ -759,6 +759,7 @@ public:
   void pg_stat_queue_dequeue(PG *pg);
 
   void init();
+  void start_shutdown();
   void shutdown();
 
   // split
diff --git a/src/osd/PGBackend.cc b/src/osd/PGBackend.cc
index 39e4b7809eb..ad78d1f5526 100644
--- a/src/osd/PGBackend.cc
+++ b/src/osd/PGBackend.cc
@@ -80,7 +80,7 @@ void PGBackend::rollback(
 }
 
 
-void PGBackend::on_change(ObjectStore::Transaction *t)
+void PGBackend::on_change_cleanup(ObjectStore::Transaction *t)
 {
   dout(10) << __func__ << dendl;
   // clear temp
@@ -94,7 +94,6 @@ void PGBackend::on_change(ObjectStore::Transaction *t)
       ghobject_t(*i, ghobject_t::NO_GEN, get_parent()->whoami_shard().shard));
   }
   temp_contents.clear();
-  _on_change(t);
 }
 
 coll_t PGBackend::get_temp_coll(ObjectStore::Transaction *t)
diff --git a/src/osd/PGBackend.h b/src/osd/PGBackend.h
index b164872a2ef..59efef1c955 100644
--- a/src/osd/PGBackend.h
+++ b/src/osd/PGBackend.h
@@ -300,12 +300,16 @@
 
    virtual void check_recovery_sources(const OSDMapRef osdmap) = 0;
 
+
+   /**
+    * clean up any temporary on-disk state due to a pg interval change
+    */
+   void on_change_cleanup(ObjectStore::Transaction *t);
    /**
     * implementation should clear itself, contexts blessed prior to on_change
     * won't be called after on_change()
     */
-   void on_change(ObjectStore::Transaction *t);
-   virtual void _on_change(ObjectStore::Transaction *t) = 0;
+   virtual void on_change() = 0;
    virtual void clear_state() = 0;
 
    virtual void on_flushed() = 0;
diff --git a/src/osd/ReplicatedBackend.cc b/src/osd/ReplicatedBackend.cc
index c7d8b6b1560..5e079760f72 100644
--- a/src/osd/ReplicatedBackend.cc
+++ b/src/osd/ReplicatedBackend.cc
@@ -192,8 +192,9 @@ void ReplicatedBackend::clear_state()
   pull_from_peer.clear();
 }
 
-void ReplicatedBackend::_on_change(ObjectStore::Transaction *t)
+void ReplicatedBackend::on_change()
 {
+  dout(10) << __func__ << dendl;
   for (map<ceph_tid_t, InProgressOp>::iterator i = in_progress_ops.begin();
        i != in_progress_ops.end();
        in_progress_ops.erase(i++)) {
diff --git a/src/osd/ReplicatedBackend.h b/src/osd/ReplicatedBackend.h
index 26f8f517171..5e1f0ec1266 100644
--- a/src/osd/ReplicatedBackend.h
+++ b/src/osd/ReplicatedBackend.h
@@ -69,7 +69,7 @@ public:
     OpRequestRef op
     );
 
-  void _on_change(ObjectStore::Transaction *t);
+  void on_change();
   void clear_state();
   void on_flushed();
 
diff --git a/src/osd/ReplicatedPG.cc b/src/osd/ReplicatedPG.cc
index 373fc0e354d..a14dac81f6d 100644
--- a/src/osd/ReplicatedPG.cc
+++ b/src/osd/ReplicatedPG.cc
@@ -9221,7 +9221,7 @@ void ReplicatedPG::apply_and_flush_repops(bool requeue)
   while (!repop_queue.empty()) {
     RepGather *repop = repop_queue.front();
     repop_queue.pop_front();
-    dout(10) << " applying repop tid " << repop->rep_tid << dendl;
+    dout(10) << " canceling repop tid " << repop->rep_tid << dendl;
     repop->rep_aborted = true;
     if (repop->on_applied) {
       delete repop->on_applied;
@@ -9318,6 +9318,9 @@ void ReplicatedPG::on_shutdown()
   cancel_copy_ops(false);
   cancel_flush_ops(false);
   apply_and_flush_repops(false);
+
+  pgbackend->on_change();
+
   context_registry_on_change();
 
   osd->remote_reserver.cancel_reservation(info.pgid);
@@ -9441,7 +9444,8 @@ void ReplicatedPG::on_change(ObjectStore::Transaction *t)
   // any dups
   apply_and_flush_repops(is_primary());
 
-  pgbackend->on_change(t);
+  pgbackend->on_change_cleanup(t);
+  pgbackend->on_change();
 
   // clear snap_trimmer state
   snap_trimmer_machine.process_event(Reset());
diff --git a/src/osd/osd_types.cc b/src/osd/osd_types.cc
index 8c27f06840f..9cde9dcfe89 100644
--- a/src/osd/osd_types.cc
+++ b/src/osd/osd_types.cc
@@ -1060,8 +1060,56 @@ void pg_pool_t::encode(bufferlist& bl, uint64_t features) const
     return;
   }
 
-  __u8 encode_compat = 5;
-  ENCODE_START(15, encode_compat, bl);
+  if ((features & CEPH_FEATURE_OSD_POOLRESEND) == 0) {
+    // we simply added last_force_op_resend here, which is a fully
+    // backward compatible change.  however, encoding the same map
+    // differently between monitors triggers scrub noise (even though
+    // they are decodable without the feature), so let's be pendantic
+    // about it.
+    ENCODE_START(14, 5, bl);
+    ::encode(type, bl);
+    ::encode(size, bl);
+    ::encode(crush_ruleset, bl);
+    ::encode(object_hash, bl);
+    ::encode(pg_num, bl);
+    ::encode(pgp_num, bl);
+    __u32 lpg_num = 0, lpgp_num = 0;  // tell old code that there are no localized pgs.
+    ::encode(lpg_num, bl);
+    ::encode(lpgp_num, bl);
+    ::encode(last_change, bl);
+    ::encode(snap_seq, bl);
+    ::encode(snap_epoch, bl);
+    ::encode(snaps, bl, features);
+    ::encode(removed_snaps, bl);
+    ::encode(auid, bl);
+    ::encode(flags, bl);
+    ::encode(crash_replay_interval, bl);
+    ::encode(min_size, bl);
+    ::encode(quota_max_bytes, bl);
+    ::encode(quota_max_objects, bl);
+    ::encode(tiers, bl);
+    ::encode(tier_of, bl);
+    __u8 c = cache_mode;
+    ::encode(c, bl);
+    ::encode(read_tier, bl);
+    ::encode(write_tier, bl);
+    ::encode(properties, bl);
+    ::encode(hit_set_params, bl);
+    ::encode(hit_set_period, bl);
+    ::encode(hit_set_count, bl);
+    ::encode(stripe_width, bl);
+    ::encode(target_max_bytes, bl);
+    ::encode(target_max_objects, bl);
+    ::encode(cache_target_dirty_ratio_micro, bl);
+    ::encode(cache_target_full_ratio_micro, bl);
+    ::encode(cache_min_flush_age, bl);
+    ::encode(cache_min_evict_age, bl);
+    ::encode(erasure_code_profile, bl);
+    ENCODE_FINISH(bl);
+    return;
+  }
+
+  ENCODE_START(15, 5, bl);
   ::encode(type, bl);
   ::encode(size, bl);
   ::encode(crush_ruleset, bl);
diff --git a/src/rgw/rgw_rados.h b/src/rgw/rgw_rados.h
index 05525ab83b0..ad29f2de815 100644
--- a/src/rgw/rgw_rados.h
+++ b/src/rgw/rgw_rados.h
@@ -165,7 +165,8 @@ struct RGWObjManifestRule {
     ::decode(start_ofs, bl);
     ::decode(part_size, bl);
     ::decode(stripe_max_size, bl);
-    ::decode(override_prefix, bl);
+    if (struct_v >= 2)
+      ::decode(override_prefix, bl);
     DECODE_FINISH(bl);
   }
   void dump(Formatter *f) const;