Single-node locking module

• Volume Group locks are stored in /var/lock/lvm using flock() on files that bear the name of the Volume Group after the prefix V_.

• Conceptually, all Physical Volumes that do not belong to any real Volume Group are considered to belong to an Orphan Volume Group that uses the special lock P_orphans.

• Logical Volume locks are not stored anywhere. Instead, requests for locks are converted directly into corresponding actions.