Abstract: A method includes monitoring a number of read access requests to an address for data stored on a backing store. The method also includes comparing the number of read access requests to a read access threshold. The read access threshold includes a threshold number of read access requests for the address. The method also includes caching data corresponding to a write access request to the address in response to determining that the number of read access requests satisfies the read access threshold.

Abstract: An apparatus, system, and method are disclosed for data block usage information synchronization for a non-volatile storage volume. The method includes referencing first data block usage information for data blocks of a non-volatile storage volume managed by a storage manager. The first data block usage information is maintained by the storage manager. The method also includes synchronizing second data block usage information managed by a storage controller with the first data block usage information maintained by the storage manager. The storage manager maintains the first data block usage information separate from second data block usage information managed by the storage controller.

Abstract: An apparatus, system, and method are disclosed for managing eviction of data. A grooming cost module determines a grooming cost for a selected region of a nonvolatile solid-state cache. The grooming cost includes a cost of evicting the selected region of the nonvolatile solid-state cache relative to other regions. A grooming candidate set module adds the selected region to a grooming candidate set in response to the grooming cost satisfying a grooming cost threshold. A low cost module selects a low cost region within the grooming candidate set. A groomer module recovers storage capacity of the low cost region.

Abstract: An apparatus, system, and method are disclosed for data block usage information synchronization for a non-volatile storage volume. The method includes referencing first data block usage information for data blocks of a non-volatile storage volume managed by a storage manager. The first data block usage information is maintained by the storage manager. The method also includes synchronizing second data block usage information managed by a storage controller with the first data block usage information maintained by the storage manager. The storage manager maintains the first data block usage information separate from second data block usage information managed by the storage controller.

Abstract: Data is stored on a non-volatile storage media in a sequential, log-based format. The formatted data defines an ordered sequence of storage operations performed on the non-volatile storage media. A storage layer maintains volatile metadata, which may include a forward index associating logical identifiers with respective physical storage units on the non-volatile storage media. The volatile metadata may be reconstructed from the ordered sequence of storage operations. Persistent notes may be used to maintain consistency between the volatile metadata and the contents of the non-volatile storage media. Persistent notes may identify data that does not need to be retained on the non-volatile storage media and/or is no longer valid.

Abstract: A method includes monitoring a number of read access requests to an address for data stored on a backing store. The method also includes comparing the number of read access requests to a read access threshold. The read access threshold includes a threshold number of read access requests for the address. The method also includes caching data corresponding to a write access request to the address in response to determining that the number of read access requests satisfies the read access threshold.

Abstract: Apparatuses, systems, and methods are disclosed for managing multiple sets of metadata. A method includes maintaining a first set of metadata on a volatile recording medium and a second set of metadata on a non-volatile recording medium. The first and second sets of metadata are associated with one or more logical addresses for data stored on the non-volatile recording medium. The first and second sets of metadata relate to a state of the data. A method includes updating the second set of metadata in response to a first operation performed on the data. The second set may be updated based on the first operation. A method includes updating the first set of metadata in response to a subsequent operation performed on the data. The first set may be updated based on the first operation.

Abstract: Techniques are disclosed relating to storing translations in memory that are usable to access data on a recording medium. In one embodiment, a request is sent for a memory allocation within a non-pageable portion of a memory in a computer system. Responsive to the request, allocated memory is received. Translations usable to map logical addresses to physical addresses within a storage device are stored within the allocated memory. In some embodiments, the translations are usable to access an area within the storage device used to store pages evicted from the memory. In one embodiment, a size of the memory allocation is determined based on a size of the area. In another embodiment, a size of the memory allocation is determined based on a size of a partition including the area. In some embodiments, the storage device is a solid-state storage array.

Abstract: Apparatuses, systems, and methods are disclosed for managing contents of a cache. A method includes receiving a read request for data stored in a non-volatile cache. A method includes determining whether a read request satisfies a frequent read threshold for a cache. A method includes writing data of a read request forward on a sequential log-based writing structure of a cache in response to determining that the read request satisfies a frequent read threshold.

Abstract: An apparatus, system, and method are disclosed for caching data on a solid-state storage device. The solid-state storage device maintains metadata pertaining to cache operations performed on the solid-state storage device, as well as storage operations of the solid-state storage device. The metadata indicates what data in the cache is valid, as well as information about what data in the nonvolatile cache has been stored in a backing store. A backup engine works through units in the nonvolatile cache device and backs up the valid data to the backing store. During grooming operations, the groomer determines whether the data is valid and whether the data is discardable. Data that is both valid and discardable may be removed during the grooming operation. The groomer may also determine whether the data is cold in determining whether to remove the data from the cache device. The cache device may present to clients a logical space that is the same size as the backing store.

Abstract: An apparatus and system are disclosed for a storage area network (“SAN”). In one embodiment, a computer system includes an internal storage device and an internal storage controller. In this embodiment, the internal storage controller is configured to implement a SAN that includes at least the internal storage device and a storage device external to the computer system. In this embodiment, the internal storage controller is further configured to service a storage request received from a client that involves data stored by the internal storage device. In this embodiment, the internal storage controller is configured to communicate with the external storage device via a network.

Abstract: An apparatus, system, and method are disclosed for managing a cache. A cache interface module provides access to a plurality of virtual storage units of a solid-state storage device over a cache interface. At least one of the virtual storage units comprises a cache unit. A cache command module exchanges cache management information for the at least one cache unit with one or more cache clients over the cache interface. A cache management module manages the at least one cache unit based on the cache management information exchanged with the one or more cache clients.

Abstract: An apparatus and system are disclosed for an in-server storage area network (“SAN”). A first storage controller is included within a first server. The first storage controller controls at least one storage device. The first server includes a network interface shared by the first server and the first storage controller. A storage communication module is included that facilitates communication between the first storage controller and at least one device external to the first server, where the communication between the first storage controller and the external device is independent from the first server. An in-server SAN module is included that services a storage request using at least one of a network protocol and a bus protocol. The in-server SAN module services the storage request independent from the first server, the service request received from a client.

Abstract: An apparatus, system, and method are disclosed for caching data. A storage request module detects an input/output (“I/O”) request for a storage device cached by solid-state storage media of a cache. A direct mapping module references a single mapping structure to determine that the cache comprises data of the I/O request. The single mapping structure maps each logical block address of the storage device directly to a logical block address of the cache. The single mapping structure maintains a fully associative relationship between logical block addresses of the storage device and physical storage addresses on the solid-state storage media. A cache fulfillment module satisfies the I/O request using the cache in response to the direct mapping module determining that the cache comprises at least one data block of the I/O request.

Abstract: An apparatus, system, and method are disclosed for bad block remapping. A bad block identifier module identifies one or more data blocks on a solid-state storage element as bad blocks. A log update module writes at least a location of each bad block identified by the bad block identifier module into each of two or more redundant bad block logs. A bad block mapping module accesses at least one bad block log during a start-up operation to create in memory a bad block map. The bad block map includes a mapping between the bad block locations in the bad block log and a corresponding location of a replacement block for each bad block location. Data is stored in each replacement block instead of the corresponding bad block. The bad block mapping module creates the bad block map using one of a replacement block location and a bad block mapping algorithm.

Abstract: An apparatus, system, and method are disclosed for data storage with progressive redundant array of independent drives (“RAID”). A storage request receiver module, a striping module, a parity-mirror module, and a parity progression module are included. The storage request receiver module receives a request to store data of a file or of an object. The striping module calculates a stripe pattern for the data. The stripe pattern includes one or more stripes, and each stripe includes a set of N data segments. The striping module writes the N data segments to N storage devices. Each data segment is written to a separate storage device within a set of storage devices assigned to the stripe. The parity-mirror module writes a set of N data segments to one or more parity-mirror storage devices within the set of storage devices. The parity progression module calculates a parity data segment on each parity-mirror device in response to a storage consolidation operation, and stores the parity data segments.

Abstract: An apparatus, system, and method are disclosed for bad block remapping. A bad block identifier module identifies one or more data blocks on a solid-state storage element as bad blocks. A log update module writes at least a location of each bad block identified by the bad block identifier module into each of two or more redundant bad block logs. A bad block mapping module accesses at least one bad block log during a start-up operation to create in memory a bad block map. The bad block map includes a mapping between the bad block locations in the bad block log and a corresponding location of a replacement block for each bad block location. Data is stored in each replacement block instead of the corresponding bad block. The bad block mapping module creates the bad block map using one of a replacement block location and a bad block mapping algorithm.

Abstract: Data is stored on a non-volatile storage media in a sequential, log-based format. The formatted data defines an ordered sequence of storage operations performed on the non-volatile storage media. A virtual storage layer maintains volatile metadata, which may include a forward index associating logical identifiers with respective physical storage units on the non-volatile storage media. The volatile metadata may be reconstructed from the ordered sequence of storage operations. Persistent notes may be used to maintain consistency between the volatile metadata and the contents of the non-volatile storage media. Persistent notes may identify data that does not need to be retained on the non-volatile storage media and/or is no longer valid.

Abstract: An apparatus, system, and method are disclosed for efficiently mapping virtual and physical addresses. A forward mapping module uses a forward map to identify physical addresses of data of a data segment from a virtual address. The data segment is identified in a storage request. The virtual addresses include discrete addresses within a virtual address space where the virtual addresses sparsely populate the virtual address space. A reverse mapping module uses a reverse map to determine a virtual address of a data segment from a physical address. The reverse map maps the data storage device into erase regions such that a portion of the reverse map spans an erase region of the data storage device erased together during a storage space recovery operation. A storage space recovery module uses the reverse map to identify valid data in an erase region prior to an operation to recover the erase region.

Abstract: An apparatus, system, and method are disclosed for managing contents of a cache. A storage request module monitors storage requests received by a cache. The storage requests include read requests and write requests. A read pool module adjusts a size of a read pool of the cache to maximize a read hit rate of the storage requests. A dirty write pool module adjusts a size of a dirty write pool of the cache to maximize a dirty write hit rate of the storage requests.