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:


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