Is this a BUG REPORT or FEATURE REQUEST?:

/kind feature

What happened:
We can install OpenSDS with lvm and ceph supported, but once the OpenSDS has been installed without lvm and ceph supported, we have no way to add lvm and ceph backend to OpenSDS.,

What you expected to happen:
Ceph and lvm backend can be added to OpenSDS even though they are not configred to be supported when installing OpenSDS

How to reproduce it (as minimally and precisely as possible):

Anything else we need to know?:

Environment:

• Hotpot(release/branch) version:latest
• OS (e.g. from /etc/os-release):Ubuntu 16.04.2
• Kernel (e.g. uname -a):
• Install tools:
• Others: