Abstract: A method and system for generating and restoring a backup image are disclosed. A server receives a request, which includes a backup path, to generate a backup image. The server generates a backup image offset map that indicates a relative location where a file is stored in the backup image before file data has been written to the backup image. The server stores the backup image offset map in a portion of the backup image on a storage device. The backup image offset map comprises an array having a number of elements equal to a number of inodes on a file system that hosts a backup path, an element of the array representing an inode on the file system, and indicates the relative location where a file that is associated with a number of the inode is stored in the backup image.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for quantifying a spatial distribution of accesses to storage systems and for determining spatial locality of references to storage addresses in the storage systems, are described. In one aspect, a method includes determining a measure of spatial distribution of accesses to a data storage system based on multiple distinct groups of accesses to the data storage system, and adjusting a caching policy used for the data storage system based on the determined measure of spatial distribution.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, can perform data caching. In some implementations, a method and system include receiving information that includes a logical address, allocating a physical page in a non-volatile memory structure, mapping the logical address to a physical address of the physical page, and writing, based on the physical address, data to the non-volatile memory structure to cache information associated with the logical address. The logical address can include an identifier of a data storage device and a logical page number.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, manage metadata for virtual volumes. In some implementations, a method and system include defining multiple metadata blocks in a persistent storage, including information that links a virtual address space to the storage system, where the defining includes, for at least one of the multiple metadata blocks, determining multiple output addresses corresponding to the storage system, and writing the multiple output addresses and an identifier corresponding to the multiple metadata blocks in a metadata block in the persistent storage. In some implementations, a method and system include reading the multiple metadata blocks into the memory from the persistent storage, including identifying the metadata block based on the identifier; receiving an input address of the virtual address space; and obtaining a corresponding output address to the storage system using the multiple metadata blocks in the memory.

Abstract: A method and system for generating and restoring a backup image are disclosed. According to one aspect of the invention, a server receives a request to generate a backup image. The request includes a selection a backup path. Based on the backup path, the server generates a list of files and/or directories to backup. However, before writing the files to the backup image, the server generates an offset map to indicate where in the backup image each file will be located. The server then writes the offset map to the backup image. During a restore operation, the server receives a request to restore files, including a selection of files and/or directories to restore. The server reads the offset map from the beginning of the backup image to quickly determine the location in the backup image of selected files.

Abstract: A system includes a control module, a location description module, and a page invalidation module. The control module is configured to write data received from a host to a storage medium, read data from the storage medium, and cache data from at least one of the host and the storage medium in a flash memory. The location description module is configured to map one of a valid and invalid state to a physical location of a subset of data in the flash memory. The page invalidation module is configured to receive a command from one of the host and the control module that includes an address corresponding to the subset and an instruction to set a state of the physical location to the invalid state. The page invalidation module is further configured to set the state of the physical location to the invalid state in response to the command.

Abstract: The parallel RS-RAID data storage architecture can aggregate that data and checksums within each cluster into intermediate or partial sums that are transferred or distributed to other clusters. The use of intermediate data symbols, intermediate checksum symbols, cluster configuration information on the assignment of data storage devices to clusters and the operational status of data storage devices, and the like, can reduce the computational burden and latency for the error correction calculations while increasing the scalability and throughput of the parallel RS-RAID distributed data storage architecture.

Abstract: A method and system for generating and restoring a backup image are disclosed. According to one aspect of the invention, a server receives a request to generate a backup image. The request includes a selection a backup path. Based on the backup path, the server generates a list of files and/or directories to backup. However, before writing the files to the backup image, the server generates an offset map to indicate where in the backup image each file will be located. The server then writes the offset map to the backup image. During a restore operation, the server receives a request to restore files, including a selection of files and/or directories to restore. The server reads the offset map from the beginning of the backup image to quickly determine the location in the backup image of selected files.