Abstract: Systems, methods, apparatus and software can implement a multipathing driver using dynamically loadable device policy modules that provide device specific functionality for providing at least one of input/output (I/O) operation scheduling, path selection, and I/O operation error analysis. Because the device policy modules include device specific functionality, various different devices from different manufacturers can be more efficiently and robustly supported.

Abstract: A method and system for implementing a global name space service. The method may include receiving a file system unique identifier corresponding to a particular file and a human-readable name corresponding to the same file. The method may further include binding the human-readable name to the file system unique identifier, thereby creating a mapping between the human-readable name and the file system unique identifier. The system may include a processor coupled to a memory and to a global name space service manager. The global name space service manager may be configured to receive a file system unique identifier corresponding to a particular file and a human-readable name corresponding to the same file. The global name space service manager may be further configured to bind the human-readable name to the file system unique identifier, thereby creating a mapping between the human-readable name and the file system unique identifier.

Abstract: Backup of a production instance of an application in a production machine environment is performed by creating a snapshot image that captures the state of the production machine, and then backing up the application from a backup machine created using the snapshot image. The backup of the application can be effected by shutting down the backup machine and backing up its storage, or by using backup software to act on the backup version of the application.

Abstract: A system may be provided which is operable to determine a routing node for a data object. The system can comprise an identifier generator operable to generate an identifier for the data object on the basis of data content thereof, and a lookup engine operable to compare the identifier for the data object to a routing table to determine a routing node for the data element.

Abstract: A method and apparatus of identifying and using storage properties within a file system. In particular, the invention exposes the storage property of an underlying storage volume i.e., mirrored storage, RAID storage, standard storage, archival storage and the like, to the user such that the user may select a volume with appropriate storage capabilities for their files. Furthermore, the storage property of a storage volume is used as a file property within the file system such that files may be organized using the storage property. In another embodiment of the invention, altering the storage property that is used as a file property, automatically moves the file from one storage volume type to another storage volume type in accordance with the selected storage property.

Abstract: Method, system, and apparatus for maintaining consistent images of metadata and data in a file system or other data journaling software stored on a temporal volume are presented. An intent log is maintained of all data and metadata modifying transactions, which is then relayed either asynchronously or form a last known consistent checkpoint to a requested checkpoint thereby rendering the requested checkpoint data and metadata consistent.

Abstract: A computer system or memory medium with instructions executable by a computer system to detect and/or suggest corrective actions when performance and availability are violated in an environment deploying virtualization at multiple levels. In one embodiment the computer system receives identities of a plurality of first physical storage devices, wherein storage in the plurality of first physical storage devices was logically aggregated to create a first storage object. The computer system also receives identities of a plurality of second physical storage devices, wherein storage in the plurality of second physical storage devices was logically aggregated to create a second storage object. Then, the computer system compares the identity of each of the plurality of first physical storage devices with the identities of the plurality of second physical storage devices.

Abstract: A system for communication using emulated LUN blocks in storage virtualization environments includes a first host and an off-host virtualizer. The off-host virtualizer may be configured to generate operating system metadata for a virtual storage device, and to make the operating system metadata accessible to the first host. A first layer of a storage software stack at the host may use the operating system metadata to detect the existence of the virtual storage device as an addressable storage device. The off-host virtualizer may also be configured to provide configuration information at a designated set of block addresses within the virtual storage device. A second layer of the storage software stack may be configured to read the configuration information from the designated set of blocks.

Abstract: A backup system can be provided, which system can comprise an identifier operable to identify a data object for possible backup and a generator operable to generate an identity representation for the data object on the basis of the content thereof. The identity representation can be transmitted to a backup store where it can be tested against identity representations for previously stored objects. The system can also comprise a receiver operable to receive from the backup store an indication of whether the data object described by the identity representation has previously been stored at the backup store. The system can be operable to transmit the data object to the backup store in the event that the data object described by the identity representation has not previously been stored at the backup store.

Abstract: An extensible architecture for centralized discovery and management of heterogeneous Storage Area Network (SAN) components. A SAN management server may be provided for communicating with the heterogeneous SAN components to perform centralized discovery and management of the SAN. The server may manage a data repository for storing data objects representing the components of the SAN. The SAN management server may include one or more explorers for communicating with SAN components to perform one or more discovery or management operations. Each explorer may be added to the system as a separate module. The SAN management server may receive SAN management commands and select and sequence one or more of the explorers to perform one or more SAN component discovery or management operations. The SAN management server may convert data obtained from the heterogeneous SAN components into a common data model.

Abstract: Various methods and systems are disclosed for handling I/O requests to a replica that has not yet been fully synchronized. One method involves detecting the transfer of the role of working volume from a first volume to a second volume. The second volume is configured as a replica of the first volume, but the second volume may not be fully synchronized with the first volume at the time that the role of working volume is transferred. Subsequent to the role of working volume being transferred to the second volume, a read request to the second volume is satisfied by accessing a log. The log is configured to store values that have been written to the first volume, and at least one of the values written to the first volume has not been written to the second volume.

Abstract: Embodiments of a system and method for providing service-level monitoring for applications in SANs. Embodiments may identify what applications are running on which hosts in a SAN, automatically identify which paths the applications use through the storage infrastructure to reach their storage, and may monitor SAN components of the paths. One embodiment may provide a task group monitor that monitors groups of SAN components and reports problems detected on group members at the application level. Embodiments may proactively monitor SAN infrastructure including the hardware and/or software components of storage, hosts, fabric, etc. needed for scheduled application tasks such as backup tasks and may alert the operator when problems are detected. Thus, embodiments correlate detected infrastructure problems directly to the applications that are affected, allowing these problems to be addressed at the application level, and prior to scheduled execution of tasks.

Abstract: System and method for resynchronizing mirrored volumes in a storage system. According to one embodiment, a system may include a first volume located at a primary site and associated with a first storage management device, and a second volume located at a secondary site and associated with a second storage management device, where the secondary site is coupled to the primary site via a data link, and where the second volume is configured as a mirror of the first volume. The first storage management device may be configured to convey to the second storage management device an indication of a data block written to the first volume subsequent to a failure of the data link. Dependent upon the indication, the second storage management device may be configured to create a snapshot of the data block as stored on the second volume prior to resynchronization of the data block.

Abstract: System and method for policy-based lifecycle management of data in file systems. In embodiments, an expiration policy for the files may be stored as part of the file system metadata. The expiration policy may be as simple as an expiration date for the file, or a more complex policy that specifies one or more metrics to be evaluated to determine if a file is expired. The expiration policy may also specify one or more actions to be taken if the file has expired. The expiration policy may be evaluated on attempts to access the files in the file system, on other file systems, and on backup/archive images to determine if the files are expired and thus whether access to the files is to be allowed. In one embodiment, a scan mechanism may periodically or aperiodically delete files in the file system for which the expiration date has passed.

Abstract: System and method for generating modifiable representations of system hardware and software configurations and for transferring a system to another system using the configuration representations. A configuration representation may include a backup of a system's files. A configuration representation may be modified, and may be used to restore the system to hardware that may be different than the original system's hardware. In one embodiment, a configuration transfer mechanism is provided to perform the transfer of a configuration representation from a source system to a target system. One embodiment of a configuration transfer mechanism may use one or more servers coupled to the source and target systems via a network. Another embodiment of a configuration transfer mechanism may be used to restore a source system's configuration and files from a source system directly to a target system coupled to the source system without using servers.

Abstract: A system and method related to efficiently searching for an object in a network including a plurality of realms, e.g., a plurality of local area networks (LANs). The method may ensure that nodes within a LAN are able to locate objects within that LAN using only computing resources on the local LAN. Thus, expensive WAN transfers may be avoided where possible. The system may also scale to many nodes. Nodes may not be required to know about every other node in the system. Mechanisms for re-distributing object location information among nodes as nodes are added to and removed from the system are also described.

Abstract: Procedures and systems may be used for archiving data from a secondary data set that is a stable copy of a primary data set. In one implementation, the secondary data set is a continuous data protection (CDP) copy of the primary data set. One implementation of a method includes receiving an application programming interface (API) request for archive-eligible data, gathering application data from a secondary data set, obtaining archive-eligible data from the gathered application data, and responding to the request instruction with the archive-eligible data. The gathering is performed by a gathering circuit configured to obtain information from a plurality of types of secondary data sets. The method also includes receiving API modification instructions related to the archive-eligible data, and causing the modification instruction to be performed on the primary data set.

Abstract: A system uses a protocol stack on a card external to a motherboard in a target computer system. A processor on the motherboard is able to make use of the external protocol stack during boot-up of the computer, or at any other time, so that it is not necessary to load the protocol stack into the motherboard's memory. This saves time, memory, and disk space and permits an external, managing, computer system to communicate with a computer just after power-up without loading and configuring a protocol stack so that the managing computer system can control the boot-up of the target computer system. The extra memory saved, especially, is important in running many MS-DOS applications, such as firmware flash utilities. A preferred embodiment of the invention uses a UDP/Internet Protocol (UDP/IP) stack resident in a Preboot Execution Environment (PXE) on, e.g, a network card. The approach described herein can be applied to other utilities, protocol stacks or resources (hardware and software) on other cards.

Abstract: Various embodiments of a system and method for optimizing storage library operations. In one embodiment a method may comprise storing a plurality of efficiency values indicative of relative efficiencies of storage targets in a storage library, and executing a storage library operation based on the plurality of efficiency values. Efficiency values may include, for example, information on a physical layout of the storage library. In one embodiment storage targets may include at least the following classes: a slot class, a portal class, a drive class, a picker class, and a media class. In one embodiment, executing a storage library operation based on the plurality of efficiency values may comprise selecting one or more storage targets to implement the storage library operation based on the plurality of efficiency values. For example, a drive closest to a given media unit may be selected to read the media unit.

Abstract: A method for backup and restore using inconsistent state indicators comprises identifying, from among a plurality of data objects to be backed up, one or more data objects that are in an inconsistent state, and storing inconsistent state indicators (such as modified object attributes) associated with the data objects. The method may further include generating a backup aggregate such as a snapshot of the plurality of data objects, where the backup aggregate includes backup versions of the inconsistent data objects. Prior to restoring one or more data objects from the backup aggregation, the method may include using the inconsistent state indicators to identify the backup versions that correspond to the inconsistent data objects, e.g., to exclude backup versions corresponding to inconsistent data objects from a list of full restoration candidates.