Abstract: Embodiments disclosed herein provide systems and methods for performing garbage collection in virtual environments. In a particular embodiment, a method provides performing a garbage collection process to identify at least a portion of a secondary storage volume located within a primary storage volume. The method further provides triggering a data block release process on at least a portion of the primary storage volume corresponding to the at least a portion of the secondary storage volume.

Abstract: Example apparatus and methods monitor conditions in a tiered storage system. The conditions monitored may include the availability of different numbers and types of devices including an erasure code based object storage system. The conditions monitored may also include the availability and type of devices available to the erasure code based object storage system. A redundancy policy for storing an item using the erasure code based object storage system may be determined based on the conditions. Erasure codes associated with the item may then be stored in the erasure code based object storage system as controlled, at least in part, by the redundancy policy. The redundancy policy for the erasure codes may be updated dynamically in response to changing conditions on the tiered storage system.

Abstract: Methods, apparatus, and other embodiments associated with adaptive use of erasure codes for distributed data storage systems are described. One example method includes accessing a message, where the message has a message size, selecting an encoding strategy as a function of the message size, data storage device failure statistics, data storage device wear periods, data storage space constraints, or overhead constraints, and where the encoding strategy includes an erasure code approach, generating an encoded message using the encoding strategy, generating an encoded block, where the encoded block includes the encoded message and metadata associated with the message, and storing the encoded block in the data storage system. Example methods and apparatus may employ Reed Solomon erasure codes or Fountain erasure codes. Example methods and apparatus may display to a user the storage capacity and durability of the data storage system.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media to handle unsuccessful movements of removable storage media in an automated removable media system. In a particular embodiment, a method provides receiving one or more user provided parameters that indicate one or more types of unsuccessful media move operations that should be reported as successful. The method further provides receiving a first request to move a first item of removable storage media from a first position in the automated removable media system to a second position in the automated removable media system and initiating a first move operation of the first item from the first position to the second position by at least one changer device. The method then provides determining that the first move operation resulted in one of the one or more types of unsuccessful media move operations and indicating that the first move operation was successful in response to the first request.

Abstract: Apparatus and methods are provided herein for path lookup in a hierarchical file system. An inode associated with a requested object is identified. The inode may be organized in an inode table and identified in the table using an inode number. Ancestry information and size constraint information may also be available for the inode. An inode chain associated with the pathway is identified based, at least in part, on ancestry information associated with the inode for the requested object. A size constraint analysis is performed for the requested object. The size altering operation is selectively performed based on the size constraint analysis.

Abstract: Methods, apparatus, and other embodiments associated with performing personal deduplication on a mobile device are described. One example method includes accessing a personal or context sensitive deduplication repository, where the context is based on a time of use of the mobile device, a purpose of use of the mobile device, a location of the mobile device, or an application in use by the mobile device, selectively de-duplicating data arriving at the mobile device, and selectively de-duplicating data to be transmitted by the mobile device, where the deduplication is performed using the personal or context sensitive deduplication repository. Example methods and apparatus may employ a chunking and hashing deduplication approach, a vector deduplication approach, or a delta deduplication approach.

Abstract: A tape layout module for determining a tape layout allocation strategy for laying out data on tape, the data being organized into a plurality of fixed-size subdata sets with each of the plurality of subdata sets including a plurality of codeword interleaves, the tape including a plurality of media defect characteristics, includes a tape layout optimization system including a processor that receives information on the plurality of media defect characteristics. The tape layout optimization system determines the tape layout allocation strategy based at least in part on at least one of the plurality of media defect characteristics. Additionally, the tape layout optimization system can determine the tape layout allocation strategy further based on distance spectra between pairs of the plurality of codeword interleaves. Further, the tape layout optimization system can determine the tape layout allocation strategy by selectively utilizing at least one tape layout parameter.

Abstract: The present invention is directed toward methods and systems for data de-duplication. More particularly, in various embodiments, the present invention provides systems and methods for data de-duplication that may utilize a vectoring method for data de-duplication wherein a stream of data is divided into “data sets” or blocks. For each block, a code, such as a hash or cyclic redundancy code may be calculated and stored. The first block of the set may be written normally and its address and hash can be stored and noted. Subsequent block hashes may be compared with previously written block hashes.

Abstract: Embodiments provide adaptive storage management for optimizing multi-tier data storage. A storage manager may interact with storage decision advisors. The manager may adaptively make storage management decisions (e.g., flush, evict, recall, delete) after considering recommendations from and the credibility of the storage decision advisors. The manager may update the credibility of storage decision advisors based on how their recommendations affected optimization. The manager may adaptively choose when to rebalance or reconfigure the credibility of the storage decision advisors. Storage decision advisors may themselves be adaptive. Storage decision advisors may examine credibility feedback from the storage manager to determine which recommendations were useful and which were not. Storage decision advisors may then change when they will make a recommendation, when they will abstain from making a recommendation, the type of recommendation provided, or other behavior.

Abstract: Methods and apparatus associated with data cold storage are described. Example apparatus include an array of data storage devices arranged in rows and columns. Columns of the array are orthogonal to rows. A row has an associated row-centric power supply, and a column has an associated column-centric local electronics module (LEM) that controls a data storage device in the column independently of other data storage devices in the array. Example apparatus include logics that control a power mode of a data storage device independently of other data storage devices in the array, that control a power mode of an LEM, that adaptively regulate the level of data stored in a buffer, and that determine whether a data object will be stored in the buffer or stored on a data storage device in the array, based on the probability the data object will be accessed within a threshold period of time.

Abstract: A data identification system and method for operating the data identification system are provided. The method comprises identifying processing elements contained within the storage environment, identifying virtual processing elements contained within the processing elements, identifying virtual storage elements contained within the virtual processing elements, identifying contents of the virtual storage elements, generating the file system view of the storage environment, wherein the file system view comprises the processing elements, the virtual processing elements, the virtual storage elements, and the contents of the virtual storage elements arranged in a hierarchical order. The file system view of the storage environment is then provided.

Abstract: Example apparatus and methods concern identifying an error in a file system. The error is identified during one or more b-tree traversals through the file system. A fix for the error is produced upon detecting the error. Data or metadata associated with the fix is not initially written to the file system, but instead is stored somewhere other than the file system using a copy on write approach. After the traversals are complete, the file system may be fixed using the data or metadata stored using the copy on write approach.

Abstract: The present invention is directed toward methods and systems for data de-duplication. More particularly, in various embodiments, the present invention provides systems and methods for data de-duplication that may utilize a vectoring method for data de-duplication wherein a stream of data is divided into “data sets” or blocks. For each block, a code, such as a hash or cyclic redundancy code may be calculated and stored. The first block of the set may be written normally and its address and hash can be stored and noted. Subsequent block hashes may be compared with previously written block hashes.

Abstract: Example methods and apparatus associated with a messaging policy controlled email deduplication are provided. In one example a messaging policy is accessed. It is determined whether a received message complies with the policy based on rules of the messaging policy. If a message complies with the messaging policy, the message is displayed. If the message does not comply with the messaging policy, it is determined whether the message is duplicative. If the message is deemed duplicative it is not displayed. Conversely, if the message is not deemed duplicative it is displayed.

Abstract: The present invention is directed toward methods and systems for data de-duplication. More particularly, in various embodiments, the present invention provides systems and methods for data de-duplication that may utilize a vectoring method for data de-duplication wherein a stream of data is divided into “data sets” or blocks. For each block, a code, such as a hash or cyclic redundancy code may be calculated and stored. The first block of the set may be written normally and its address and hash can be stored and noted. Subsequent block hashes may be compared with previously written block hashes.

Abstract: Example apparatus and methods provide a log structured block device for a hard disk drive (HDD). Data that is to be stored on an HDD is serialized and written as a series of data blocks using a sequential write. Information about where individual data blocks were supposed to be written (e.g., actual address, neighboring data blocks), where data blocks were actually written, and how often data blocks are accessed is maintained. During garbage collection, data blocks that are being accessed with similar frequencies may be relocated together, with the most frequently accessed (e.g., hottest) data blocks migrating to the outer cylinders of the disk and the least frequently accessed (e.g., coldest) data blocks migrating to the inner cylinders. Blocks stored in the same temperature regions that were intended to be located together when written may be repositioned to facilitate sequential reads.

Abstract: Methods and apparatus associated with storing data in high or low energy zones are described. Example apparatus include a data storage system (DSS) that protects a message using an erasure code (EC). A location in the DSS may have an energy efficiency rating or a latency. Example apparatus include circuits that produce EC encoded data that has a likelihood of use, that select a location to store the EC encoded data in the DSS based on the energy efficiency rating, the latency, or the likelihood of use, that store the EC encoded data in the location, and that compute an order of retrieval for EC encoded data stored in the location. The order of retrieval may be based on the energy efficiency rating or the latency. The EC encoded data may also have a priority based on the number of erasures for which the EC corrects.

Abstract: A data storage network is provided. The network includes a client connected to the data storage network; a plurality nodes on the data storage network, wherein each data node has two or more RAID controllers, wherein a first RAID controller of a first node is configured to receive a data storage request from the client and to generate RAID parity data on a data set received from the client, and to store all of the generated RAID parity data on a single node of the plurality of nodes.

Abstract: Example apparatus and methods produce a set of rateless erasure codes (e.g., fountain codes) for a file stored in a primary data store (e.g., hard drive) or in an archive system. The archive system may store the file in a redundant array of independent disks (RAID). A first subset of the rateless erasure codes are stored in an object storage using a synchronous protocol. A second subset of rateless erasure codes are stored in the object storage using an asynchronous protocol. The object storage system may inform the archive system when desired redundancy has been achieved or when desired redundancy has been lost. The archive system may buffer rateless erasure codes before providing the codes to the object storage to improve performance. A failure in the archive system or object storage system may be mitigated by retaining the file in the primary data store until the desired redundancy is achieved.

Abstract: A technique includes in a data storage device, sensing a plurality of data streams from a track of storage media as the media moves in a given direction using a plurality of read elements such that at least one of the read elements is redundant. The technique includes combining the data streams to generate a data stream indicating data read from the track.