Looking at 
https://access.qa.redhat.com/documentation/en/red-hat-ceph-storage/version-2/installation-guide-for-red-hat-enterprise-linux/#upgrading_ceph_storage_cluster

Section 5.2 step 6 says:

Verify you have a HEALTH_OK Ceph storage cluster and all placement groups are active+clean before moving on to the next OSD host:

At this point in the process, noout and norebalance are set, so you will always get a HEALTH_WARN.  If you wait for HEALTH_OK, it will take forever.

Something better would be:

Verify that the only health warnings are that the noout and norebalance flags are set.

ceph health

HEALTH_WARN noout,norebalance flag(s) set

After step 7, then run ceph -s to verify that the health status is HEALTH_OK