摘要:
Example apparatus, methods, and computers are configured to consider multiple lookups when making decisions concerning whether a probabilistic data structure indicates that an item is or is not present. One example method includes receiving a first response from a probabilistic data structure, where the first response indicates whether a first element is a member of a set of stored elements. The example method also includes receiving a set of second responses from the probabilistic data structure, where the set of second responses indicate whether members of a corresponding set of second elements are members of the set of stored elements. The method then provides a present/absent signal concerning whether the first element is a member of the set of stored elements. The signal is computed as a function of the first response and the set of second responses rather than merely as a function of the first response.
摘要:
An open systems based media storage library system (10) for use by one or more hosts (5) includes a first hosted partition (12A) and a pool partition (14). The first hosted partition (12A) can be accessed by one of the hosts (5). Additionally, the first hosted partition (12A) includes a plurality of first hosted resources (16, 18). The plurality of first hosted resources (16, 18) can include a plurality of first hosted storage slots (16) and a plurality of first hosted storage media (18). The plurality of first hosted storage slots (16) includes one or more first physical storage slots (16P) and one or more first logical storage slots (16L). The plurality of first hosted storage media (18) are positioned within the first physical storage slots (16P). The pool partition (14) is inaccessible by any of the hosts (5). The pool partition (14) includes a plurality of pool resources (20, 22). One of the plurality of pool resources (20, 22) is selectively assigning to the first hosted partition (12A).
摘要:
A digital data recovery system (14) for converting a suboptimal signal (18) into a converted signal (20) that closely approximates an original signal (16) includes a first data filter (22), a first interpolator (26) and a second interpolator (36). The first data filter (22) filters the suboptimal signal (18) to generate a first filtered signal (48). The first interpolator (26) receives the first filtered signal (48) and generates a first interpolated signal (52). Substantially concurrently, the second interpolator (36) receives the suboptimal signal (18) and generates a second interpolated signal (64). The digital data recovery system (14) may further comprise a second data filter (38) that receives the second interpolated signal (64) and generates a second filtered signal (66). Further, the first data filter (22) can include a set of first coefficients (50) and the second data filter (38) can include a set of second coefficients (68). Moreover, the second coefficients (68) can be updated and subsequently transformed in order to update the first coefficients (50).
摘要:
Example apparatus, methods, and computers control processing delta chunks with delta hashes. One example method includes computing a first hash for a chunk for which a duplicate determination is to be made. The first hash is suitable for making the duplicate chunk determination. The method also includes computing a delta hash for the chunk. The delta hash is suitable for making a delta chunk determination. The method controls a de-duplication logic to process the chunk as a duplicate upon determining that the first hash matches a stored first hash. The method controls the de-duplication logic to process the chunk as a delta chunk upon determining that the first hash does not match a stored first hash and that the delta hash matches a stored delta hash. Processing a chunk as a delta chunk may include storing a reference to a stored chunk and storing delta hash information.
摘要:
Systems, methods embodied on computer-readable media, and other embodiments associated with index entry eviction are described. One example method includes selecting an index entry for eviction from a bucket of index entries based on a time value, a utility value, and a precedence value. A precedence value may be a value associated with an index entry that is static over time. Additionally, results of a function that compares two precedence values may be static over time. The example method may also include providing an index entry identifier that identifies the index entry.
摘要:
A method that includes, by one or more computer systems, determining a data retrieval rate policy based on at least one data retrieval rate parameter. The method also includes determining at least one storage subsystem performance parameter. The method further includes determining a fragmentation value based on the data retrieval rate policy and the at least one storage subsystem performance parameter. The method additionally includes determining a storage subsystem fragmentation of a first data object. The storage subsystem fragmentation includes fragmenting the first data object into a plurality of first data object fragments. The method also includes deduplicating the first data object based on the fragmentation value and the storage subsystem fragmentation.
摘要:
The present invention is directed to an archival data storage system. The archival data storage system includes write once and read many (WORM) capability, data redundancy, error correction, and access control. The combination of these capabilities enable the archival storage system to be secure, error proof, and reliable. Additionally, to provide fast data access time, solid state storage devices are used in place of conventional tape drive. Solid state storage devices such as, for example, flash memory devices are fast, versatile and reliable.
摘要:
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.
摘要:
Example articles of manufacture, methods, and systems facilitate having encryption policy follow an article of manufacture like a tape cartridge. One example article of manufacture includes a media portion (e.g., tape) and a non-media portion (e.g., housing). The media portion is configured to store machine readable information. The article of manufacture could be a tape, a disk, a memory, and other computer readable media. The article of manufacture also includes an encryption policy information indicator. The encryption policy information indicator can be configured to store information that controls an encryption policy associated with the article of manufacture. Therefore, encryption policy can, for example, follow a tape cartridge rather than be resident solely in a controlling application (e.g., tape library).
摘要:
Timing recovery in partial-response-based magnetic recording systems customarily employs the “decision-directed” method wherein phase error is recovered from the differences between the noise-corrupted received signal samples and their estimated ideal (noise and phase error free) values. The filtered phase error drives a numerically-controlled oscillator which determines the instants at which the signal is resampled, attempting to place said instants at the ideal sampling times. The resampled signal contains errors due to mistiming as well as to the original corrupting noise, and these errors directly influence the success of subsequent detection. However, the noise can be reduced using adaptive linear prediction, having the effect of reducing the output error for a given noise input, or maintaining the same error for a larger noise input.