CLVM

• CLVM extends LVM2 to provide cluster-wide management of Logical Volumes.

• The LVM2 architecture was designed to be cluster-ready from the outset. Management of the LVM2 metadata – how a given Logical Volume should is constructed, for example – is completely separate from the actual use of that metadata to construct a block device in the running kernel using device-mapper.

• There are two sorts of locks:

• • Volume Group locks for metadata management;
  • Logical Volume locks for activation in the kernel.