Creating a volume group outside of CSPOC in HACMP

Creating a volume group outside of cspoc is not the recommended
method, but certainly running importvg -L will result in unpredictable
 behavior if the volume group does not already exist on the node
you're running the importvg on.
.
importvg -L is used to update a host about changes made to a volume
group, not to create a new volume group.
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Finally, since this appears to be a vio client on at least one node,
per the previous update by Jesse, the volume groups should be in
enhanced concurrent mode for fast disk takeover (HACMP does not know
how to break reserves on a vio client, so requires that there be no
reserves placed).  In that environment, you should never have to run
the varyonvg -bu/importvg -L for LVM updates, as gsclvmd will ensure
the updates are propogated across the cluster.   For a new vg, which
shouldn't be varied on after it is created, a simple importvg -y
will suffice, once it's added to the resource group and the cluster is
 synced it will be brought online correctly.