Abstract: The present invention provides for a method, system, and computer program product for managing the storage of data. Data is selectively compressed based on a pre-defined compression policy and metadata is stored for physical storage blocks. A stored compression policy identifies at least one criterion for compression, and physical blocks of data meeting the compression policy are identified. A physical block is selected as a source block for data compression, and one or more physical locations are selected as target locations. Data is read from the source block, compressed, and written to the target locations. Metadata is updated to indicate a mapping between the target locations and the virtual blocks previously mapped to the source block. Extra storage capacity can be freed up until more physical storage is ordered and installed, while more important data, such as recently or frequently accessed data, is retained in an uncompressed and accessible state.

Abstract: An apparatus is disclosed in which a storage controller cooperable with a host and a plurality of controlled storage is provided to localize an impact of a failure to a target disk in an affected segment. The storage controller includes a host write component to write a data object to a source image storage; a first copy component responsive to a first metadata state to control copying of the data object to a first target storage; a second copy component responsive to a second metadata state to perform either: copying the data object to a second target or causing the first copy component to copy the second target to the first target; and a third copy component to control cascaded copying of the data object to a third target storage. Either the second or the third copy component controls cascaded copying of a delimited data image subsequence responsive to a metadata state indicating currency of a data grain in either the second or the third target.

Abstract: An apparatus for providing an oscillating signal to a load comprises: a phase locked loop, PLL, comprising a feedback loop; a power control means for manipulating oscillating signal power; an isolator for isolating the feedback loop from the load; and a mode selector coupled to the power control means and the isolator, for controlling the power control means and the isolator so that in a steady state power mode, oscillation power is supplied to the load and in a reduced power mode, power is isolated by the isolator from the load to the feedback loop so that phase lock is maintained when the oscillation power is reduced.

Abstract: A method and apparatus is disclosed in which a storage controller cooperable with a host and a plurality of controlled storage is provided to localize an impact of a failure to a target disk in an affected segment. The storage controller includes a host write component to write a data object to a source image storage; a first copy component responsive to a first metadata state to control copying of the data object to a first target storage; a second copy component responsive to a second metadata state to perform either: copying the data object to a second target or causing the first copy component to copy the second target to the first target; and a third copy component to control cascaded copying of the data object to a third target storage. Either the second or the third copy component controls cascaded copying of a delimited data image subsequence responsive to a metadata state indicating currency of a data grain in either the second or the third target.

Abstract: An apparatus, method, and computer program for facilitating disaster recovery of a first computer system, wherein first data residing on a first storage device associated with the first computer system is recoverable from second data residing on a second storage device associated with a second computer system and wherein the second storage device is operable to have an associated state of powered up or powered down. A receiver receives an update operation for updating the second storage device. A processor updates anon-volatile storage means with the update operation, prior to update of the second storage device, wherein the non-volatile storage means is associated with the second computer system.

Abstract: An apparatus, method, and computer program for facilitating disaster recovery of a first computer system, wherein first data residing on a first storage device associated with the first computer system is recoverable from second data residing on a second storage device associated with a second computer system and wherein the second storage device is operable to have an associated state of powered up or powered down. A receiver receives an update operation for updating the second storage device. A processor updates anon-volatile storage means with the update operation, prior to update of the second storage device, wherein the non-volatile storage means is associated with the second computer system.

Abstract: A method for maintaining data access during failure of a controller in a multiple controller storage subsystem (103) is provided. The storage subsystem (103) has an array of data storage devices (109) and more than one controller (104, 105) for managing the data storage. The method comprises a first controller (201) saving its internal state information (212) and, optionally, resetting itself (213). One or more of the other controllers (202, 203) carry out the steps of pausing operation of the controller (221, 231), saving internal state information of the controller at the time of pausing (222, 232), and continuing operation of the controller (223, 233). The one or more other controllers (202, 203) may pause operation and save their internal state information when they receive a message broadcast (220, 230) from the first controller (201) which has detected an error.

Abstract: A storage controller includes an interface to host computer apparatus and an interface to a plurality of controlled storage apparatus. The storage controller comprises a host write component operable to send a request to write a data object to a source data image at one of said plurality of controlled storage apparatus; a copy component operable in response to a metadata state to control copying of said data object to a target data image in a delimited sequence of data images in a cascade at said plurality of controlled storage apparatus and a fill-in component operable in response to detection of an offline condition of a disk containing said target data image to control substitution of a fill-in disk in place of said disk containing said target data image.

Abstract: A method for data retention in a data cache and a data storage system are provided. The data storage system (100) includes a storage controller (102) with a cache (103) and a data storage means (106). The cache (103) has a first least recently used list (104) for referencing dirty data which is stored in the cache (103), and a second least recently used list (105) for clean data in the cache (103). Dirty data is destaged from the cache (103) when it reaches the tail of the first least recently used list (104) and clean data is purged from the cache (103) when it reaches the tail of the second least recently used list (105).

Abstract: A method and apparatus is disclosed in which a storage controller cooperable with a host and a plurality of controlled storage is provided to localize an impact of a failure to a target disk in an affected segment. The storage controller includes a host write component to write a data object to a source image storage; a first copy component responsive to a first metadata state to control copying of the data object to a first target storage; a second copy component responsive to a second metadata state to perform either: copying the data object to a second target or causing the first copy component to copy the second target to the first target; and a third copy component to control cascaded copying of the data object to a third target storage. Either the second or the third copy component controls cascaded copying of a delimited data image subsequence responsive to a metadata state indicating currency of a data grain in either the second or the third target.

Abstract: The present invention relates to methods of copying and updating data in a processor memory during program run-time without suspending the program's access to its data in the memory during the data-copying and updating processes. In one aspect, the invention concerns a method of copying data from processor memory to a dump memory during run-time, including determining whether data in a segment of the processor memory is to be updated by a program and copying the data to a corresponding segment in the dump memory prior to the data being updated. According to one embodiment, a data-copying instance is utilized to obtain a point-in-time image of a data content of processor memory while the program is running.

Abstract: The invention relates to caching data in a data processing system including a host computer and a storage subsystem including at least one customer disk and a cache disk. Write transactions are received specifying data to be written to at least one customer disk and these are cached in a volatile memory of the storage subsystem and written to the cache disk. The transaction data is written sequentially to the cache disk when available. In the intervening periods (i.e., when no transaction data is available), padding data is instead written sequentially to the cache disk.

Abstract: An inkjet device comprising a service station and a printhead, said service station comprising an ink spreader and a spittoon, said spittoon having an ink receiving surface arranged to receive ink spitted from said printhead, said ink spreader being arranged to spread spitted ink in a substantially unbroken layer over at least a portion said ink receiving surface.

Abstract: A method for data retention in a data cache and a data storage system are provided. The data storage system (100) includes a storage controller (102) with a cache (103) and a data storage means (106). The cache (103) has a first least recently used list (104) for referencing dirty data which is stored in the cache (103), and a second least recently used list (105) for clean data in the cache (103). Dirty data is destaged from the cache (103) when it reaches the tail of the first least recently used list (104) and clean data is purged from the cache (103) when it reaches the tail of the second least recently used list (105).

Abstract: A method for maintaining data access during failure of a controller in a multiple controller storage subsystem (103) is provided. The storage subsystem (103) has an array of data storage devices (109) and more than one controller (104, 105) for managing the data storage. The method comprises a first controller (201) saving its internal state information (212) and, optionally, resetting itself (213). One or more of the other controllers (202, 203) carry out the steps of pausing operation of the controller (221, 231), saving internal state information of the controller at the time of pausing (222, 232), and continuing operation of the controller (223, 233). The one or more other controllers (202, 203) may pause operation and save their internal state information when they receive a message broadcast (220, 230) from the first controller (201) which has detected an error.

Abstract: An arrangement and methods for operation in a cache memory system to facitate re-synchronising non-volatile cache memories (150B, 160B) following interruption in communication. A primary adapter (150) creates a non-volatile record (150C) of each cache update before it is applied to either cache. Each such record is cleared when the primary adapter knows that the cache update has been applied to both adapters' caches. In the event of a reset or other failure, the primary adapter can read the non-volatile list of transfers which were ongoing. For each entry in this list, the primary adapter negotiates with the secondary adapter (160) and transfers only the data which may be different.

Abstract: An inkjet printing device comprising first and second pens and first and second service stations, the first and second service stations being arranged in a split servicing configuration and being arranged to service the first and second pens respectively, the device being adapted to detect the failure of a said pen and to print in a reserve mode in response to the detection, the device being further adapted to implement a modified servicing routine during reserve mode printing, the modified servicing routine being adapted to omit servicing of the failed pen.

Abstract: A commerce system for computer-based trading is disclosed. The system allows a user to interact with one or more vendors' e-commerce servers. The system comprising a relay server, that is operative to transfer page requests from a user to a vendor's e-commerce server, and transfer page data from the vendor's e-commerce server to the user having applied transforms to data received form the vendor's e-commerce server. The relay server is also operative to process purchase requests generated by a user to relating to e-commerce transactions with the vendor's server. In particular embodiments, the relay server can maintain a virtual shopping basket that contains items selected for purchase from several vendors' sites and can implement payment for these items in a single payment process.

Abstract: The invention relates to caching data in a data processing system including a host computer and a storage subsystem including at least one customer disk and a cache disk. Write transactions are received specifying data to be written to at least one customer disk and these are cached in a volatile memory of the storage subsystem and written to the cache disk. The transaction data is written sequentially to the cache disk when available. In the intervening periods (i.e., when no transaction data is available), padding data is instead written sequentially to the cache disk.