available參数在man info help中均无此參数，事实上參数为：activate

写此此。值得用的人注意。

available 參数实为：

 -a, --activate [a|e|l]{y|n}

              Controls the availability of the logical volumes for use.  Communicates with the kernel device-mapper driver via libdevmapper to  activate

              (-ay) or deactivate (-an) the logical volumes. If autoactivation option is used (-aay), the logical volume is activated only if it matches

              an item in the activation/auto_activation_volume_list set in lvm.conf.  If this list is not set,  then  all  volumes  are  considered  for

              autoactivation. The autoactivation is not yet supported for logical volumes that are part of partial or clustered volume groups.

If  clustered locking is enabled, -aey will activate exclusively on one node and -aly will activate only on the local node.  To deactivate

              only on the local node use -aln.  Logical volumes with single-host snapshots are always activated exclusively because  they  can  only  be

              used on one node at once.