mgr/volume: default to 16 PGs (min) for metadata pool

Set the min so that the pg_autoscaler won't scale it back down.  Choose
something large enough that even for a large FS we'll do reasonably well
distributing the metadata workload across OSDs.

Signed-off-by: Sage Weil <sage@redhat.com>

diff --git a/src/pybind/mgr/volumes/module.py b/src/pybind/mgr/volumes/module.py
index 63f8d0764e75f421375617858788bce59ed4a23b..163f0d0a84bae7d7a59a406ac740ff532336f3f0 100644 (file)
--- a/src/pybind/mgr/volumes/module.py
+++ b/src/pybind/mgr/volumes/module.py
@@ -131,7 +131,8 @@ class Module(orchestrator.OrchestratorClientMixin, MgrModule):
         r, outb, outs = self.mon_command({
             'prefix': 'osd pool create',
             'pool': mdp_name,
-            'pg_num': 8
+            'pg_num': 16,
+            'pg_num_min': 16,
         })
         if r != 0:
             return r, outb, outs