ceph tuning

I'm going to make a new ceph test cluster and have some tuning questions.

We'll be using a 4 disk raid-10 on each node + a hot spare . There will be one OSD per node. We do not need super fast I/O , instead our priority is high availability + always great keyboard response. We'll use this ssd for journal: Intel DC S3700 Series 200GB .

Does anyone know how we could set these:

* replica of 2

* permanently set OSD noout ?

*the "mon osd downout subtree limit" set to "host"



thank you and best regards
Rob