Abstract: An apparatus, method and computer program operable in a network controls consistency guarantees of a plurality of data copies in a storage apparatus, and includes: a lease control component for extending a lease to the storage apparatus; and a consistency freeze/thaw component responsive to a failure indication for initiating a consistency freeze action at the storage apparatus prior to expiration of the current group lease period. It may further include a timer component for waiting the apparatus for a predetermined period after the consistency freeze action, where the consistency freeze/thaw component is operable to initiate a thaw action at the storage apparatus.

Abstract: Write requests from host computers are processed in relation to a thin provisioning storage subsystem. A write request is received from a host computer. The write request identifies a first virtual disk that has been previously assigned to the host computer. It is determined whether the first virtual disk has to be allocated additional physical storage locations of the thin provisioning storage subsystem for storing data associated with the write request. In response to determining that the virtual disk has to be allocated additional physical storage locations, the following is performed. First, a quantity of free space remaining unallocated within physical storage locations of the thin provisioning storage subsystem is determined. Second, where the quantity of free space remaining unallocated within the physical storage locations satisfies a policy threshold associated with a second virtual disk, the second virtual disk is write-inhibited. The first and second virtual disks can be different.

Abstract: A data processing system using a client-server configuration includes a method and apparatus for simultaneously generating multiple copies of data sets in multiple storage pools. Simultaneous copies of data sets may be made for storage pools having LAN-free paths in addition to storage pools having only access from a LAN path.

Abstract: Disclosed are a system, a method, and article of manufacture to provide a compensator for a synchronous sampling servo control system.