Driver to leverage the features of IBM GPFS file system

IBM General Parallel File System (GPFS) is a mature cluster file system used by some of the largest enterprises and supercomputers in the world. It offers a number of specific features and optimizations for hosting master images, instances, and volumes. In particular, the bock-level format-agnostic copy-on-write mechanism enables quick volume provisioning through snapshots. The File Placement Optimization (FPO) feature allows specifying the set of nodes and their local disks where the physical blocks of a particular volume file and its replicas should be allocated. Transparent block-level replication, controllable per file, provides resilient volumes.

This driver implements an initial set of features using the primitives of the GPFS file system.