Abstract: Attributing consumed storage capacity among entities storing data in a storage array includes: identifying a data object stored in the storage array and shared by a plurality of entities, where the data object occupies an amount of storage capacity of the storage array; and attributing to each entity a fractional portion of the amount of storage capacity occupied by the data object.

Abstract: Attributing consumed storage capacity among entities storing data in a storage array includes: identifying a data object stored in the storage array and shared by a plurality of entities, where the data object occupies an amount of storage capacity of the storage array; and attributing to each entity a fractional portion of the amount of storage capacity occupied by the data object.

Abstract: A system and method for performing coarse-grained deduplication of volume regions. A storage controller detects that a first region of a first volume is identical to a second region of a second volume, wherein the first volume points to a first medium and the second volume points to a second medium. In response to detecting the identical regions, the storage controller stores an indication that the first range of the first medium underlies the second range of the second medium. Also in response to detecting the identical regions, the mappings associated with the second range of the second medium are invalidated.

Abstract: A system and method for maintaining the safety of volume operations. A storage controller receives a request to delete a first volume. In response to this request, the storage controller can delete a link between the first volume and its anchor medium. The storage controller can also delay the deletion of the first volume's anchor medium. Later on, if the user wishes to restore the first volume, the storage controller can reconnect the first volume to its previous anchor medium, effectively restoring the first volume to its former state and undoing the deletion operation.

Abstract: A system and method for performing copy offload operations. When a copy offload operation from a first volume (pointing to a first medium) to a second volume (pointing to a second medium) is requested, the copy offload operation is performed without accessing the data being copied. A third medium is created, and the first medium is recorded as the underlying medium of the third medium. The first volume is re-pointed to the third medium. Also, a fourth medium is created, the second volume is re-pointed to the fourth medium, and the second medium is recorded as the underlying medium of the targeted range of the fourth medium. All other ranges of the fourth medium have the second medium as their underlying medium.

Abstract: A system and method for exposing volumes with underlying read-write mediums to user operations. When a medium is in the process of being replicated to a storage array, a volume which relies on the medium can be exposed to user operations (e.g., snapshots, read and write operations) once the portions of the medium which underlie the volume have been replicated. The volume can be exposed to user operations while one or more other portions of the medium are unfilled and while the medium is in an intermediate read-write state.

Abstract: A system and method for performing copy offload operations. When a copy offload operation from a first volume (pointing to a first medium) to a second volume (pointing to a second medium) is requested, the copy offload operation is performed without accessing the data being copied. A third medium is created, and the first medium is recorded as the underlying medium of the third medium. The first volume is re-pointed to the third medium. Also, a fourth medium is created, the second volume is re-pointed to the fourth medium, and the second medium is recorded as the underlying medium of the targeted range of the fourth medium. All other ranges of the fourth medium have the second medium as their underlying medium.

Abstract: A system and method for performing search optimization operations. In order to optimize lookups for received data requests, a storage controller attempts to collapse the medium graph, thus reducing the number of mediums in which the storage controller must look to find a given block. One technique for collapsing the medium graph involves promoting individual mappings from a lower-level medium to a higher-level medium. Another technique for collapsing the medium graph involves pushing medium range pointers higher up in the medium mapping table to reduce the number of mediums that must be searched.

Abstract: A system and method for creating and managing snapshots. Mediums are recorded and maintained, all of which are read-only except for the most recent mediums in use by a volume. Multiple volumes may be maintained, including a first volume which points to a first medium. When a snapshot of the first volume is taken, a second medium is created that points to the first medium. The first volume is also updated to point to the second medium. The first medium becomes the underlying medium of the second medium, and lookups are performed initially on the second medium and then on the first medium if the data is not located in the second medium.

Abstract: A system and method for performing coarse-grained deduplication of volume regions. A storage controller detects that a first region of a first volume is identical to a second region of a second volume, wherein the first volume points to a first medium and the second volume points to a second medium. In response to detecting the identical regions, the storage controller stores an indication that the first range of the first medium underlies the second range of the second medium. Also in response to detecting the identical regions, the mappings associated with the second range of the second medium are invalidated.

Abstract: A system and method for maintaining the safety of volume operations. A storage controller receives a request to delete a first volume. In response to this request, the storage controller can delete a link between the first volume and its anchor medium. The storage controller can also delay the deletion of the first volume's anchor medium. Later on, if the user wishes to restore the first volume, the storage controller can reconnect the first volume to its previous anchor medium, effectively restoring the first volume to its former state and undoing the deletion operation.

Abstract: A system and method for performing copy offload operations. When a copy offload operation from a first volume (pointing to a first medium) to a second volume (pointing to a second medium) is requested, the copy offload operation is performed without accessing the data being copied. A third medium is created, and the first medium is recorded as the underlying medium of the third medium. The first volume is re-pointed to the third medium. Also, a fourth medium is created, the second volume is re-pointed to the fourth medium, and the second medium is recorded as the underlying medium of the targeted range of the fourth medium. All other ranges of the fourth medium have the second medium as their underlying medium.