`check_call` does raises exceptions, this is also very well documented in the actual function (see: https://github.com/ceph/ceph-deploy/blob/master/ceph_deploy/util/wrappers.py#L11-22)

But regardless, the brownie points here are that the wrapper will handle that for you, no need to dance with try/except all over the place. 

This is exactly how all the `install` process for ceph-deploy happens too.