Abstract: A doubly mapped redundant array of independent nodes (doubly mapped RAIN) for data storage is disclosed. A doubly mapped RAIN cluster can be allocated on top of one or more real data clusters. The real data cluster can be N nodes by M disks by L extents. A doubly mapped RAIN cluster can be N? nodes by M? disks by L? extents, where N? is less than, or equal to N. Mapping of data storage locations in a doubly mapped RAIN cluster can facilitate use of a real cluster at a different granularity than in either a conventionally administered real cluster or in a singly mapped RAIN. The topology of a doubly mapped RAIN can be constrained via rules related to correlation of real disks to mapped nodes, correlation of real extents to mapped nodes, correlation or real extents to mapped disks, etc.

Abstract: A doubly mapped redundant array of independent nodes (doubly mapped RAIN) for data storage is disclosed. A doubly mapped RAIN cluster can be allocated on top of one or more real data clusters. The real data cluster can be N nodes by M disks by L extents. A doubly mapped RAIN cluster can be N? nodes by M? disks by L? extents, where N? is less than, or equal to N. Mapping of data storage locations in a doubly mapped RAIN cluster can facilitate use of a real cluster at a different granularity than in either a conventionally administered real cluster or in a singly mapped RAIN. The topology of a doubly mapped RAIN can be constrained via rules related to correlation of real disks to mapped nodes, correlation of real extents to mapped nodes, correlation or real extents to mapped disks, etc.