Abstract: Utilizing a non-repeating identifier to encrypt data, including: receiving a request to write data to a storage device; selecting a segment-offset pair where the data will be stored, where the selected segment-offset pair is unique to every other segment-offset pair utilized during the lifetime of the storage device; and encrypting the data in dependence upon an identifier of the segment-offset pair.

Abstract: A system and method for efficiently maintaining metadata stored among a plurality of solid-state storage devices. A data storage subsystem supports multiple mapping tables. Records within a mapping table are arranged in multiple levels. Each level stores at least pairs of a key value and a physical pointer value. The levels are sorted by time. New records are inserted in a created new highest (youngest) level. No edits are performed in-place. A data storage controller determines both a cost of searching a given table exceeds a threshold and an amount of memory used to flatten levels exceeds a threshold. In response, the controller incrementally flattens selected levels within the table based on key ranges. After flattening the records in the selected levels within the key range, the records may be removed from the selected levels. The process repeats with another different key range.

Abstract: A system and method for efficiently storing data in a storage system. A data storage subsystem includes multiple data storage locations on multiple storage devices in addition to at least one mapping table. A data storage controller determines whether data to store in the storage subsystem has one or more patterns of data intermingled with non-pattern data within an allocated block. Rather than store the one or more pattern on the storage devices, the controller stores information in a header on the storage devices. The information includes at least an offset for the first instance of a pattern, a pattern length, and an identification of the pattern. The data may be reconstructed for a corresponding read request from the information stored in the header.

Abstract: Utilizing a non-repeating identifier to encrypt data, including: receiving a request to write data to a storage device; selecting a segment-offset pair where the data will be stored, where the selected segment-offset pair is unique to every other segment-offset pair utilized during the lifetime of the storage device; and encrypting the data in dependence upon an identifier of the segment-offset pair.

Abstract: A system and method for efficiently maintaining metadata stored among a plurality of solid-state storage devices. A data storage subsystem supports multiple mapping tables. Records within a mapping table are arranged in multiple levels. Each level stores at least pairs of a key value and a physical pointer value. The levels are sorted by time. New records are inserted in a created new highest (youngest) level. No edits are performed in-place. A data storage controller determines both a cost of searching a given table exceeds a threshold and an amount of memory used to flatten levels exceeds a threshold. In response, the controller incrementally flattens selected levels within the table based on key ranges. After flattening the records in the selected levels within the key range, the records may be removed from the selected levels. The process repeats with another different key range.

Abstract: A system and method for efficiently distributing data among multiple storage devices. A data storage array receives read and write requests from multiple client computers. The data storage array includes multiple storage devices, each with multiple allocation units (AUs). A storage controller within the data storage array determines a RAID layout for use in storing data. In response to determining a failure of a first AU, the storage controller begins reconstructing in a second AU the data stored in the first AU. For read and write requests targeting data in the first AU, the request is serviced by the first AU responsive to determining no error occurs when accessing the first AU.

Abstract: A system and method for efficiently storing data in a storage system. A data storage subsystem includes multiple data storage locations on multiple storage devices in addition to at least one mapping table. A data storage controller determines whether data to store in the storage subsystem has one or more patterns of data intermingled with non-pattern data within an allocated block. Rather than store the one or more pattern on the storage devices, the controller stores information in a header on the storage devices. The information includes at least an offset for the first instance of a pattern, a pattern length, and an identification of the pattern. The data may be reconstructed for a corresponding read request from the information stored in the header.

Abstract: Methods are described that allow disk drives, such as shingle-written magnetic recording (SMR) drives, to recover an Indirection Address Table mapping of LBAs to PBAs after an emergency power off (EPO). Indirection Address Table (IAT) snapshots are periodically written inline with user data stores, and in one embodiment Cumulative Delta Lists (CDLs) with incremental address update information are stored between snapshots. In an embodiment of the invention, when an imminent loss of power is detected, the current CDL, covering IAT updates not yet written to disk, is saved to a nonvolatile memory. The IAT snapshots combined with the set of CDLs provide the information needed to recreate the current Indirection Address Table when power is restored after an emergency power loss. In an alternative embodiment the CDL is obviated by including metadata in the sector that encodes the address indirection mapping and the last snapshot ID.

Abstract: A method for implementing data storage and a dual port, dual element storage device are provided. A storage device includes a predefined form factor including a first port and a second port, and a first storage element and a second storage element. A controller coupled between the first port and second port, and the first storage element and second storage element controls access and provides two separate data paths to the first storage element and second storage element.

Abstract: A method is described for allowing disk drives, such as shingle-written magnetic recording (SMR) drives, to be shipped for customer use with portions of the magnetic media being left untested. The testing is then completed by the drive self-testing in the field. The drive is made functional at the factory by fully testing at least one operational set of regions including an I-region, an E-region and a write cache region. The operational set of regions works as a separate self-contained virtual disk drive and can be used immediately. The remaining untested areas on the media can be tested in the field by a background task and/or when the first write command is received that requires a new track or operational set of regions (on-the fly testing).

Abstract: A hard disk drive (HDD) minimizes the effects of far track erasure (FTE) by counting the number of writes to the data tracks and incrementing counters based on the known effect of FTE on each track. The extent of the FTE effect is determined for each track within a range of tracks of the track being written, and based on the relative FTE effect for all the tracks in the range a count increment (CI) is determined for each track within the range. A counter is maintained for each track. For every writing to a track, a count for each track within a range of the track being written is increased by the CI value associated with the track number within the range. When the count value for a track reaches a predetermined threshold the data is read from that track and rewritten, preferably to the same track.

Abstract: A method is described for allowing disk drives, such as shingle-written magnetic recording (SMR) drives, to be shipped for customer use with portions of the magnetic media being left untested. The testing is then completed by the drive self-testing in the field. The drive is made functional at the factory by fully testing at least one operational set of regions including an I-region, an E-region and a write cache region. The operational set of regions works as a separate self-contained virtual disk drive and can be used immediately. The remaining untested areas on the media can be tested in the field by a background task and/or when the first write command is received that requires a new track or operational set of regions (on-the fly testing).

Abstract: Methods are described that allow disk drives, such as shingle-written magnetic recording (SMR) drives, to recover an Indirection Address Table mapping of LBAs to PBAs after an emergency power off (EPO). Indirection Address Table (IAT) snapshots are periodically written inline with user data stores, and in one embodiment Cumulative Delta Lists (CDLs) with incremental address update information are stored between snapshots. In an embodiment of the invention, when an imminent loss of power is detected, the current CDL, covering IAT updates not yet written to disk, is saved to a nonvolatile memory. The IAT snapshots combined with the set of CDLs provide the information needed to recreate the current Indirection Address Table when power is restored after an emergency power loss. In an alternative embodiment the CDL is obviated by including metadata in the sector that encodes the address indirection mapping and the last snapshot ID.

Abstract: A data storage device encrypts data stored in non-volatile memory using a bulk encryption key. The data storage device uses a key derivation function to generate an initial encryption key. The data storage device then wraps an intermediate encryption key with the initial encryption key and stores the wrapped intermediate key in the non-volatile memory. The data storage device wraps the bulk encryption key with the intermediate encryption key and stores the wrapped bulk encryption key in the non-volatile memory. The data storage device can unwrap the wrapped intermediate key to generate the intermediate encryption key using the initial encryption key. The data storage device can unwrap the wrapped bulk encryption key to generate the bulk encryption key using the intermediate encryption key. The data storage device decrypts data stored in the non-volatile memory using the bulk encryption key.

Abstract: A method and apparatus are provided for implementing secure erase for solid state drives (SSDs). An encryption key is used to encrypt data being written to SSD. A controller identifies a key storage option, and responsive to the identified key storage option, stores a key for data encryption and decryption. The controller deletes the key within the SSD responsive to the identified key storage option, ensuring that once the key is deleted, the key is not recoverable and data is effectively erased.

Abstract: A magnetic recording hard disk drive (HDD) has at least one read/write head that accesses more than one disk surface. The HDD is able to transfer data to and from the host computer seamlessly without interruption during the time the head is being moved from one disk surface to another disk surface. Nonvolatile solid state memory is associated with pairs of disk surfaces. During the time of a head transfer from one disk surface in the pair to the other disk surface, data is read from or written to the associated nonvolatile memory. The data is first read from or written to one disk surface, then from or to the nonvolatile memory, and then, after completion of the head transfer, from or to the other disk surface, thereby allowing seamless uninterrupted transfer of data.

Abstract: A hard disk drive (HDD) minimizes the effects of far track erasure (FTE) by counting the number of writes to the data tracks and incrementing counters based on the known effect of FTE on each track. The extent of the FTE effect is determined for each track within a range of tracks of the track being written, and based on the relative FTE effect for all the tracks in the range a count increment (CI) is determined for each track within the range. A counter is maintained for each track. For every writing to a track, a count for each track within a range of the track being written is increased by the CI value associated with the track number within the range. When the count value for a track reaches a predetermined threshold the data is read from that track and rewritten, preferably to the same track.

Abstract: A data storage device has a data storage medium. A data storage capacity of the data storage device is divided into slices. Each slice has a set of sectors. Data storage device firmware is configured to store copies of a system image in the slices on the data storage device. Each of the slices stores a different copy of the system image.

Abstract: A hard disk drive (HDD) uses adaptive counting of writes to the data tracks to minimize the effect of adjacent track encroachment (ATE). The tracks are grouped into segments and a counter is associated with each segment, but the number of tracks in a segment varies or adapts depending on the number of writes to the segment. When the count for the number of writes to a segment reaches a threshold, the segment is divided into a number of segments with fewer tracks. The original segment no longer exists and does not require memory to store its count. This process continues until a segment reaches a predetermined minimum number of tracks. When the count for the number of writes to a segment with the minimum number of tracks reaches a threshold, all of the tracks in that segment, and tracks radially adjacent to and on both sides of the segment, are read and rewritten.

Abstract: The invention is a storage device which implements a write barrier command and provides means for a host to designate other write commands as being sensitive or insensitive to the existence of write barrier commands. The device can optimize the execution of commands by changing the order of execution of write commands that are insensitive to write barrier command. In an embodiment of the invention a flag associated with the write command indicates whether the command is sensitive or insensitive to the existence of write barrier commands. In an embodiment of the invention the write barrier command can be implemented as a write command with a flag that indicates whether the command is a write barrier command. In one embodiment of the invention the queue of commands and data to be written to the media is stored in a non-volatile cache.