Abstract: One embodiment is directed to a method and apparatus for modifying a configuration of a computer system including a host computer and at least one computer system resource accessible to at least one application program executing on the host computer. The computer system is dynamically reconfigured, without reinitializing the host computer or the application program, to alter a manner in which the at least one application program accesses the at least one computer system resource. Another embodiment is directed to a method and apparatus for responding to changes in a configuration of the computer system impacting a manner in which the at least one computer system resource is accessed by the host computer. Information relating to a first configuration of the computer system at a first point in time is stored, the first configuration relating to a first manner of accessing the at least one computer system resource by the host computer.

Abstract: A method and apparatus for manipulating data in a storage device that is coupled to a host computer. Manipulations that can be performed by the storage device include moving non-contiguous blocks of data between the host computer and the storage device in a single operation. Other manipulations can be performed directly by the storage device without passing data to or from the host computer and include copying data from one logical object that is defined on the host computer to another, initializing, backing-up, transforming, or securely deleting a logical object that is defined by the host computer with a single command. In one embodiment, an application programming interface is provided that allows a relationship between logical objects on a host computer and storage locations on a storage device to be communicated between the host computer and the storage device.

Abstract: One embodiment is directed to a method and apparatus for modifying a configuration of a computer system including a host computer and at least one computer system resource accessible to at least one application program executing on the host computer. The computer system is dynamically reconfigured, without reinitializing the host computer or the application program, to alter a manner in which the at least one application program accesses the at least one computer system resource. Another embodiment is directed to a method and apparatus for responding to changes in a configuration of the computer system impacting a manner in which the at least one computer system resource is accessed by the host computer. Information relating to a first configuration of the computer system at a first point in time is stored, the first configuration relating to a first manner of accessing the at least one computer system resource by the host computer.

Abstract: A storage controller for controling access to data storage has a memory and at least one data port for a data network including host processors. The memory is programmed to define a respective specification for each host processor of a respective subset of the data storage to which access by the host processor is restricted, and each specification is associated with a host identifier stored in the memory. When the storage controller receives a data access request from a host processor, it decodes a host identifier from the data access request, and searches the memory for a host identifier matching the host identifier decoded from the request. Upon finding a match, the respective specification of the respective subset for the host processor is accessed to determine whether or not storage specified by the storage access request is contained in the respective subset. If so, then storage access can continue, and otherwise, storage access is denied.

Abstract: One aspect is directed to a method for storing, in a persistent manner, a state of the storage process such that the state of the storage operation may be recovered if the storage operation is interrupted. Another aspect is directed to a method and apparatus that stores the state of a storage operation in a non-volatile memory of a computer that stores data on a storage system. Another aspect is directed to a method for recovering the state of the storage process without having to re-perform storage operations. Another aspect is directed to maintaining state information for other purposes such as monitoring access to data storage locations.

Abstract: A management information transfer system is disclosed for use in connection with a network including one or more host computers and a mass storage subsystem interconnected by a plurality of switching nodes, the management information transfer system being configured to transfer processed management information to a management service center located remotely from the network. The management information transfer system includes a management server that is configured to receive management information from the switching nodes, and possibly the host computers, which may be directed to failures or other malfunctions in connection with their operations. The management server is configured to perform a filtering operation in connection with the management information that it receives from the switching nodes using filtering policies that may be established by, for example, a network administrator.

Abstract: An apparatus has host ports for coupling hosts to data storage devices. The data storage devices are configured into logical storage units, and the apparatus is programmed with a mapping of the hosts to respective logical storage units. The apparatus decodes a host identifier and a logical storage unit specification from each data access request received at each host port, and determines whether or not the decoded host identifier and logical storage unit specification are in conformance with the mapping in order to permit or deny data access of the logical storage unit through the host port. For example, the apparatus includes a switch for routing the data storage access requests from the host ports to ports that provide access to the data storage, and a set of logical volumes of storage are accessible from each of the ports that provide access to the data storage.

Abstract: A data storage system includes methods and apparatus that provide volumes for access by host computing devices. The volumes can have a storage size that is independently configurable from an actual amount of data storage that may or may not be associated with the volume. The volumes also have a persistent identifier. The volumes can have any amount of associated storage space allocated to the volume, including none, within the data storage system. Since the storage size and associated storage space are each independently configurable from each other, host that interface with the data storage system can perceive the volumes as being larger than they really are. A dynamic volume configuration technique is provided which allows storage space within storage devices in the data storage system to be dynamically associated and disassociated (i.e., added and removed) from the volumes on an as-needed basis, without requiring disruption of host activities with respect to the volumes.

Abstract: A data management technique for managing accesses to data at a shared storage system includes a filter at the storage system. The filter is coupled to a configuration table, which identifies which of a number of coupled host processors have accesses to each of the resources at the device. During operation, requests received from the host devices are filtered by the filter, and only those requests to resources that the individual host devices have privilege to access are serviced. Advantageously, data security is further enhanced by authenticating each of the requests received by the storage system to verify that the host processor that is represented as forwarding the request is the indicated host processor. In addition, transfers of data between the storage system and the host processor may be validated to ensure that data was not corrupted during the data transfer.

Abstract: A method of managing workflows related to storage services provided by a service provider to a customer (via a management system) is presented. The management system includes a Web server and a workflow process. The Web server presents to a customer a task screen (or set of task screens) for a customer-selected work order request type so that the customer can prepare and submit a work order request to the management system. After receiving the work order request, the Web server uses information contained in and associated with the request to create a database object that includes some or all of the following elements: customer identifier; work order identifier, date/time of request; request state (e.g., new, open or closed); type of request; parameters or arguments to the request; and any textual description provided by the customer. The Web server stores the object in a database.

Abstract: A data network includes a switch that links a number of host processors to shared resources such as network ports of a cached storage subsystem. The switch routes resource requests from its inputs to selected ones of its outputs in accordance with programmed routing information. The routing information is changed dynamically based on measured loading characteristics of requests from the switch inputs or the respective hosts, in order to reduce the probability of blocked paths. In a specific example, respective subsets of output ports of the switch are assigned to each respective input port, the loading of each input port of the switch is measured, and the respective subset of output ports assigned to each input port are repetitively changed, and the respective subset of an input port is changed in response to blocking of the output ports assigned to the input port.

Abstract: One aspect is directed to a computer system including a host computer having an application space and defining a repository of logical objects visible thereto, and a storage system that a defines a physical space wherein data representing the repository is stored. The repository is mapped from application space to physical space to create mapping information identifying which units of storage in physical space store the repository, and the mapping information is made visible to the application space. Another aspect is directed to executing an incremental operation on a repository of logical objects. A further aspect is directed to a storage system that identifies to the host accesses to a repository of logical objects based upon accesses to corresponding units of storage in physical space. A further aspect is directed to determining that a subset of the logical objects in a repository satisfy a particular selection criterion, and transferring the subset over a network from a first to a second storage system.

Abstract: In a data storage subsystem providing data storage to host processors, a process of configuration defines a subset of the data storage that each host may access. A vector specification is a convenient mechanism for specifying a set of storage volumes that a host may access. For example, for each host processor, there is stored in memory of the data storage subsystem a list of contiguous ranges or vectors of the storage volumes that the host may access. To determine whether or not a specified logical volume number is included in the vector, a mudulus of the stride of the vector is computed from the difference between the address of the specified logical volume and the beginning address of the vector, and the modulus is compared to zero. To provide a mapping between logical unit numbers specified by the host and the logical volumes, a contiguous range of logical unit numbers may also be specified for each contiguous range or vector of storage volumes.

Abstract: A storage controller has at least one physical data port for a data network including host processors. The storage controller is programmed to provide a plurality of virtual ports for access to storage, and a virtual switch for routing storage access requests from the physical port to the virtual ports. The virtual ports and the virtual switch are defined by software. The virtual ports appear to the hosts as physical ports in the data network. For example, in a Fiber-Channel network, the virtual ports have World Wide Names (WWNs) and are assigned temporary addresses (S_IDs), and the virtual switch provides a name server identifying the WWNs and S_IDs of the virtual ports. For convenient partitioning of storage among host processors, one or more virtual ports are assigned to each host, and a set of storage volumes are made accessible from each virtual port.

Abstract: An object is authenticated by transmitting a random number to the object. The object has an integrated circuit chip including a memory and encryption circuitry. The memory stores information defining an encryption scheme preassigned to the object. The encryption circuitry reads the memory, and encrypts the random number according to the encryption scheme defined by the information read from the memory to produce encrypted data. The memory cannot be read from any output of the integrated chip, and the chip is constructed so that it is virtually impossible to recover the information contained in the memory by visual inspection, probing, or disassembly of the chip. The object is authenticated by checking whether the encrypted data is a correct result of encrypting the data using the encryption scheme pressigned to the object. The method can be used in a data processing system to authenticate each message transmitted by a host processor to a data processing device.

Abstract: A computer including an interpreter that maps logical user write requests to physical block level write requests, a host storage driver having a disk driver interface for receiving block level write requests, a host storage disk connected to be controlled by disk control signals of the host storage driver, and a mirror system having a disk driver interface to the interpreter and a remote procedure call interface to a remote archive repository, the mirror system sending write requests and data to be written from the interpreter to the host storage driver and to the remote archive repository.

Abstract: Method and apparatus directed to a computer system including a host computer and an intelligent storage system that stores data accessed by the host computer, the computer system including a plurality of logical volumes of data that are visible to the host computer and the storage system and that are perceived by the host computer as comprising a plurality of raw storage devices, the storage system including a plurality of physical storage devices and at least one mapping layer that maps the plurality of logical volumes to the plurality of physical storage devices so that the data in each of the plurality of logical volumes is stored on at least one of the plurality of physical storage devices. One aspect of the invention is directed to providing the host computer with information identifying, for at least one of the plurality of logical volumes, which ones of the plurality of physical storage devices store data included in the at least one of the plurality of logical volumes.

Abstract: An object is authenticated by transmitting a random number to the object. The object has an integrated circuit chip including a memory and encryption circuitry. The memory stores information defining an encryption scheme preassigned to the object. The encryption circuitry reads the memory, and encrypts the random number according to the encryption scheme defined by the information read from the memory to produce encrypted data. The memory cannot be read from any output of the integrated chip, and the chip is constructed so that it is virtually impossible to recover the information contained in the memory by visual inspection, probing, or disassembly of the chip. The object is authenticated by checking whether the encrypted data is a correct result of encrypting the data using the encryption scheme pressigned to the object.

Abstract: Method and apparatus for managing access to one of a plurality of raw storage devices in a computer system including a host computer and a storage system that is coupled to the host computer and that stores data accessed by the host computer. The computer system includes a plurality of logical volumes of data that are visible to the host computer and the storage system and are perceived by the host computer as comprising the plurality of raw storage devices. In accordance with one aspect of the invention, a request to perform an action on the one of the plurality of raw storage devices can be granted, even when the requester has less than system administrator access privileges. In accordance with another aspect of the invention, the one of the plurality of raw storage devices may have associated access privileges information.

Abstract: In an aspect, the invention features a method of storing data in a digital data storage system that includes a plurality of disk drives. The method involves receiving data at the data storage system; compressing the received data to generate a compressed version of the data; storing the received data on a first set of disk drives among the plurality of disk drives; and storing the compressed version of the received data on a parity disk drive so that the parity drive stores data that is redundant of data that is stored on the first set of drives.