Abstract: A CAS data storage system replicates data on a non-CAS storage device. The CAS storage device recognizes duplicate data and stores the data only once, whereas the non-CAS device does not recognize duplication of data and requires full storage of the data. The CAS data storage device saves on redundant data transfer by transferring, in the case of duplicate data, the address of a primary location at which the data is stored and the address of the current duplication. The CAS data storage system includes a hash?address table for this purpose. The non-CAS storage device then copies its own data from the primary location into the current location.

Abstract: A disk array memory system comprises: a plurality of disks in a disk array for storage of content data and parity data in stripes, content data in a same stripe sharing parity bits of said parity data, each disk having a spare disk capacity including at least some of a predefined array spare capacity, said array spare capacity providing a dynamic space reserve over said array to permit data recovery following a disk failure event; a cache for caching content data prior to writing to said disk array; and a controller configured to select a stripe currently having a largest spare stripe capacity, for a current write operation of data from said cache, thereby to write all said data of said current write operation on a same stripe, thereby to maximize sharing of parity bits per write operation and minimize separate parity write operations.

Abstract: A redundant array of independent disk (RAID) memory storage system comprising data storage blocks arranged in a first plurality of data rows and a second plurality of data columns, wherein parity data is stored in additionally defined parity blocks, and wherein numbers of data blocks in respective columns are different, to accommodate the additional diagonal parity data block that the geometry of the system requires. The system is suitable for an SSD array in which sequential disk readout is not required.

Abstract: A CAS data storage method and apparatus comprising: receiving input data including a succession of data items with corresponding logical addresses at a source CAS data storage space for storage therein and for replication at a destination CAS data storage space, generating a hash key for each data item at the source storage space, comparing respective hash keys with hash keys stored at a hash key storage table, to determine whether respective further data items are already present at the destination storage device; transferring respective data items to the destination storage space if no match is made to a hash key stored at the hash key storage table, but not transferring respective further data items if a match is made to a hash key stored at the hash key storage table, thereby transferring to the destination storage space only unique data items.

Abstract: A CAS data storage system with one or more source CAS data storage spaces and one or more destination CAS data storage spaces, and a communication line therebetween, receives input data at the source storage space for local storage and for replication to the destination CAS storage space. CAS metadata is used in the replication procedure between the two separate CAS storage spaces. Thus, data at the source storage space is used to form an active buffer for transfer to the destination storage space, the active buffer holding a hash result of the respective data item and a storage address. The system detects whenever there is more than one data item in said active buffer sharing a same storage address and upon such detection transfers a respective hash result of only the last of the data items.

Abstract: A device for scalable block data storage and retrieval uses content addressing. Data storage devices store data blocks, and are connected over a network to computing modules. The modules comprise control modules and data modules and carry out content addressing for both storage and retrieval. The network defines separate control paths via the control modules and data paths via the data modules.