Abstract: According to one embodiment, a request is received for obtaining a consistent point of data stored in a file system of a storage system having a plurality of storage units. In response to the request, retrieving a prime dependency list from a first prime segment stored in a first of the storage units, where the prime dependency list includes information identifying at least a second prime segment stored in a second of the storage units. The first and second prime segments collectively form a prime segment representing a consistent view of the file system. Each of the prime segments listed in the prime dependency list is ascertained in an attempt to generate the consistent point of data.

Abstract: According to one embodiment, in response to a request for verifying a first prime representing a consistent point of a file system of a storage system having a plurality of storage units, each of a plurality of prime segments collectively representing the first prime is examined to determine whether the corresponding prime segment has been previously verified. Each of the prime segments is stored in one of the storage units, respectively. At least a first of the prime segments that has not been previously verified is verified, without verifying a second of the prime segments that has been previously verified. The first prime, when at least the first prime segment has been successfully verified, can be used to construct the consistent point of the file system.

Abstract: According to one embodiment, a file system (FS) of a storage system is partitioned into a plurality of FS partitions, where each FS partition stores segments of data files. In response to an input and output (IO) request for accessing a first of the FS partitions, a second of the FS partitions is selected that is currently in a ready state for access. The second FS partition is then removed from the ready state for access. The first FS partition is brought into a ready state for access.

Abstract: According to one embodiment, in response to a request to write a prime segment of a file system of a storage system having a plurality of storage units, one or more of the storage units are identified based on a prime segment write-map (PSWM). The PSWM includes information indicating which of the storage units to which a next prime should be written. The prime segment is then written in the one or more storage units identified from the PSWM, without writing the prime segment to a remainder of the storage units. The prime segment represents at least a portion of a prime that contains metadata representing a consistent point of data stored in the file system.

Abstract: A method of data caching for compliance and storage systems that provide keyword search query based access to documents computes a value for each data document based on a document information-retrieval relevancy metric for user keyword queries and a recency, frequency of each query. The values are adapted to changing query frequencies and popularities. Then selecting and evicting documents from a cache can be based on the values according to a knapsack solution. A weight is computed for each query such that recent, more frequent queries get a higher weight. A information-retrieval metric is used for measuring a relevancy of a document for a query. A weighted sum is taken of the information-retrieval metric times a query weight over all queries.

Abstract: A trustworthy inverted index system processes records to identify features for indexing, generates posting lists corresponding to features in a dictionary, maintains in a storage cache a tail of at least one of the posting lists to minimize random I/Os to the index, determines a desired number of the posting lists based on a desired level of insertion performance, a query performance, or a size of the storage cache, and reads a posting list corresponding to a search feature in a query to identify records that comprise the search feature. The system maps the features in the dictionary to the desired number of posting lists. The system uses a jump pointer to point from one entry to the next in the posting lists based on increasing values of entries in the posting lists.

Abstract: A method of data caching for compliance and storage systems that provide keyword search query based access to documents computes a value for each data document based on a document information-retrieval relevancy metric for user keyword queries and a recency, frequency of each query. The values are adapted to changing query frequencies and popularities. Then selecting and evicting documents from a cache can be based on the values according to a knapsack solution. A weight is computed for each query such that recent, more frequent queries get a higher weight. A information-retrieval metric is used for measuring a relevancy of a document for a query. A weighted sum is taken of the information-retrieval metric times a query weight over all queries.

Abstract: A trustworthy inverted index system processes records to identify features for indexing, generates posting lists corresponding to features in a dictionary, maintains in a storage cache a tail of at least one of the posting lists to minimize random I/Os to the index, determines a desired number of the posting lists based on a desired level of insertion performance, a query performance, or a size of the storage cache, and reads a posting list corresponding to a search feature in a query to identify records that comprise the search feature. The system maps the features in the dictionary to the desired number of posting lists. The system uses a jump pointer to point from one entry to the next in the posting lists based on increasing values of entries in the posting lists.