After enable_dev, the following commands were not
consistently seeing the pv on it.
Alasdair explained, "whenever enabling/disabling devs
outside the tools (and you aren't trying to test how
the tools cope with suddenly appearing/disappering
devices) use "vgscan""
aux disable_dev $dev2
aux enable_dev $dev1
+vgscan
vgcreate $vg1 $dev1
UUID1=$(vgs --noheading -o vg_uuid $vg1)
aux disable_dev $dev1
aux enable_dev $dev2
+vgscan
vgcreate $vg1 $dev2
UUID2=$(vgs --noheading -o vg_uuid $vg1)
aux enable_dev $dev1
+# need vgscan after enabling/disabling devs
+# so that the next commands properly see them
+vgscan
+pvs $dev1
+pvs $dev2
vgs -o+vg_uuid >err
cat err
grep $UUID1 err
not grep $UUID2 err
aux enable_dev $dev2
+vgscan
aux disable_dev $dev1
vgs -o+vg_uuid >err
grep $UUID2 err
not grep $UUID1 err
aux enable_dev $dev1
+vgscan