Abstract: A method and apparatus are disclosed for increasing virtual storage capacity in on-demand storage systems. The method utilizes data compression to selectively compress data stored in a storage resource to reduce the utilization of physical storage space whenever such physical resources have been over committed and the demand for physical storage exceeds its availability. In one exemplary embodiment, the utilization of the capacity of a shared storage resource is monitored and data is selected for compression based on the utilization. The compression of the selected data is triggered in response to the monitoring results. In addition, policies and rules are defined that determine which data is selected for compression.

Abstract: Two methods (native and clone) are used for installing software, such as an operating system, on client system(s) booting from shared storage. The native installation method configures an interconnection network to create an exclusive communication zone between the client system and the shared storage system and installs the operating system on the client system using the exclusive communication zone. After the software is installed, the method terminates the exclusive communication zone. The clone installation method utilizes a point-in-time copy feature of the shared storage system to clone an operating system drive instantaneously. After the drive is cloned, it is logically attached to a new client and the operating system is customized for that client.

Abstract: A method and service creates and maintains a virtual point-in-time copy of source data stored within a source storage unit. The method/service receives at least one request to create a point-in-time copy of the source data. However, instead of creating a copy of the source data, the invention creates a target storage unit mapping table within a target storage unit or other storage units managed by the same storage system. This target storage unit mapping table contains pointers to the source data. In addition, the invention maintains a modification space within the target storage unit or other storage units managed by the same storage system. Each portion of the modification space is associated with a given target storage unit. The modification space only stores changes to the source data that are unique to the corresponding target storage unit.

Abstract: A method (and system) for detecting intrusions to stored data includes creating a point-time-copy of a logical unit, and comparing at least a portion of the point-time-copy with a previous copy of the logical unit. The method (and system) monitors access to a data storage system and detects an intrusion or any other intentional or unintentional, unwanted modification to data stored in the data storage system. The method (and system) also recovers data once an intrusion or other unwanted modification is detected.

Abstract: We separate the control functions of the I/O from the actual caching and transfer of data. This is referred herein as “disk improvements.” For caching, this enables improved utilization of bandwidth and memory. For transfers of data, bandwidth is improved while retaining security. Also in the present invention, we utilize unused portions of host systems to serve as a cache. This is referred herein as “cache enhancements.

Abstract: In a computer system having an operating system and a compressed main memory defining a physical memory and a real memory characterized as an amount of main memory as seen by a processor, and including a compressed memory hardware controller device for controlling processor access to the compressed main memory, there is provided a system and method for managing real memory usage comprising: a compressed memory device driver for receiving real memory usage information from the compressed memory hardware controller, the information including a characterization of the real memory usage state: and, a compression management subsystem for monitoring the memory usage and initiating memory allocation and memory recovery in accordance with the memory usage state, the subsystem including mechanism for adjusting memory usage thresholds for controlling memory state changes.