Description of problem: Introduce support for new PV type. ATM lvm2 does support PERMANENT PVs - if such PV is missing, it's causing error reports in lvm2 command. We would like to support OPTIONAL PVs - such a PV could be available, but when when it's missing it's the correct state - it's 'another kind of' MISSING handling. The limitation is - there must be always at least 1 PERMANENT PV in a VG to hold all the metadata. Such optional PV does not hold metadata. Also it's based on previous work of supporting new PV flag pv-in-use. Example of use case: Having multiple nodes - accessing clustered VG on all nodes, but then nodes may use local devices as well - e.g. local SSD storage user may want to use for caching. Other use case could be attaching optional PV as USB as a member of VG. Version-Release number of selected component (if applicable): 2.02.141 How reproducible: Steps to Reproduce: 1. 2. 3. Actual results: Expected results: Additional info: