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 and apparatus for deferring media writes for emulation drives are provided. By deferring media writes using non-volatile storage, the performance penalty associated with RMW operations may be minimized. Deferring writes may allow the RMW operations to be done while the disk drive is idle. Further, deferring writes may also allow data blocks to be accumulated over time, allowing a full (4K) disk drive block size to be written with a simple write operation, thus making a RMW unnecessary.

Abstract: A magnetic disk for a hard disk drive comprising a plurality of physical sector sizes is disclosed. The magnetic disk includes a first sector size area physically formatted according to a first physical sector size and a second sector size area physically formatted according to a second physical sector size different from the first sector size by a multiple of the first sector size wherein the second sector size can be presented externally as multiple sectors of said first sector size.

Abstract: A disk drive that includes nonvolatile memory monitors the drive's reliability-related parameters to detect real or potential failure events, and records failure-related data in nonvolatile memory, rather than in reserved areas of the disks. The monitoring may be by running a diagnostic routine or by regular or periodic monitoring of disk drive sensors, like temperature and shock sensors. The failure events to be monitored and recorded may include defective data sectors. When a new defective sector is detected after the disk drive has been put into operation, that defective sector is taken out of service and its logical block address (LBA) is mapped to a memory space in the nonvolatile memory rather to a reserved spare sector on the disk.

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 magnetic disk for a hard disk drive comprising a plurality of physical sector sizes is disclosed. The magnetic disk includes a first sector size area physically formatted according to a first physical sector size and a second sector size area physically formatted according to a second physical sector size different from the first sector size by a multiple of the first sector size wherein the second sector size can be presented externally as multiple sectors of said first sector size.

Abstract: A method and apparatus for deferring media writes for emulation drives are provided. By deferring media writes using non-volatile storage, the performance penalty associated with RMW operations may be minimized. Deferring writes may allow the RMW operations to be done while the disk drive is idle. Further, deferring writes may also allow data blocks to be accumulated over time, allowing a full (4K) disk drive block size to be written with a simple write operation, thus making a RMW unnecessary.

Abstract: WORM safeguards are provided in a magnetic disk drive in which the disks are pre-magnetized or pre-recorded such that all magnetic domains on each recording surface are completely aligned pointing in the same direction. A special write head which can magnetically write only in the direction opposite to the pre-magnetization orientation is also provided.

Abstract: A mobile computing hard disk drive has both a flash memory device and a DRAM device, with the HDD controller managing data storage between disk, DRAM, and flash both when write requests arrive and when the HDD is idle to optimize flash memory device life and system performance.

Abstract: A hybrid disk drive, i.e., a disk drive with two types of permanent storage media (conventional disk media and nonvolatile memory, such as flash memory), uses its nonvolatile memory in operational modes other than the power-save or “standby” mode wherein the disks are spun down. In a first additional mode, called a “performance” mode, one or more blocks of write data are destaged from volatile memory (the disk drive's write cache) and written to the disk and simultaneously one or more data blocks of write data are destaged from the volatile memory and written to the nonvolatile memory. In a second additional mode, called a “harsh-environment” mode, the disk drive includes one or more environmental sensors, such as temperature and humidity sensors, and the nonvolatile memory temporarily replaces the disks as the permanent storage media.

Abstract: A disk drive that includes nonvolatile memory monitors the drive's reliability-related parameters to detect real or potential failure events, and records failure-related data in nonvolatile memory, rather than in reserved areas of the disks. The monitoring may be by running a diagnostic routine or by regular or periodic monitoring of disk drive sensors, like temperature and shock sensors. The failure events to be monitored and recorded may include defective data sectors. When a new defective sector is detected after the disk drive has been put into operation, that defective sector is taken out of service and its logical block address (LBA) is mapped to a memory space in the nonvolatile memory rather to a reserved spare sector on the disk.

Abstract: A hybrid disk drive, i.e., a disk drive with two types of permanent storage media (conventional disk media and nonvolatile memory, such as flash memory), uses its nonvolatile memory in operational modes other than the power-save or “standby” mode wherein the disks are spun down. In a first additional mode, called a “performance” mode, one or more blocks of write data are destaged from volatile memory (the disk drive's write cache) and written to the disk and simultaneously one or more data blocks of write data are destaged from the volatile memory and written to the nonvolatile memory. In a second additional mode, called a “harsh-environment” mode, the disk drive includes one or more environmental sensors, such as temperature and humidity sensors, and the nonvolatile memory temporarily replaces the disks as the permanent storage media.

Abstract: For non-bursty data writes, data is written to flash memory of a hard disk drive for subsequent de-staging to disk, whereas for bursty writes data is written directly to disk.

Abstract: A RAID subsystem with a plurality of hard disk drives has each disk controller autonomously executing data scrubbing on its disks instead of requiring the RAID controller to execute data scrubbing. The data scrubbing may be interrupted upon an I/O request from the RAID controller, or it may continue if a guaranteed scrub rate is not being achieved. Data is stored in large bands of concentric data tracks, and a band may be preferentially selected for scrubbing based on frequency of reading the band, or recency of writing to the band.

Abstract: Stored data can be recovered from a disk array having at least 2n+1 physical disks that are capable of storing n physical disks worth of data when any two disks fail, or when more than two dependent disks fail. Data is stored in data stripes that are divided into n substantially equal-sized strips and are distributed across the n disks. Each data stripe has a corresponding parity strip that is generated by including the data strips in the data stripe only once when the parity strip is generated. The data strips of each data stripe, the copy of each such data strip and the corresponding parity strip are distributed across the disks in such a manner that the data strips of each data stripe, the copy of each such data strip and the corresponding parity strip are each on a respectively different disk of the disk array.

Abstract: In a disk drive that uses large block sizes (e.g., 4 KB) for storing data and that responds to read and write requests from a client that uses small block sizes (e.g., 512 bytes), at least the starting and ending 4K blocks of read data are cached. Since much disk data that is the subject of a write request is first read, upon a subsequent write request the drive controller determines whether the starting and ending blocks are in cache and if so, writes new data to those blocks, calculates a full ECC for them, and then calculates ECC for intervening blocks and writes new data to the intervening blocks. If both starting and ending blocks are not in cache the drive controller executes either a high data integrity routine or a high performance routine as chosen by the user.

Abstract: A RAID-1 system achieves sparing by allocating 1/(2N?1) of each storage device as a spare region, in a mirrored RAID-1 system having N pair of mated devices. The remaining portion of each device is partitioned into (2N?2) data partitions. If a device fails, the contents of its mate are copied into the spare regions of the other devices. This preserves fault tolerance even if a second device subsequently fails.

Abstract: A system and associated method efficiently complete write commands in an ISF disk drive/RAID system with minimal disk accesses to the underlying disk drives. The system updates data in a parity-based disk array system by receiving a write command to write new data. The present system minimizes the number of disk accesses. The present system completes the same or comparable write commands in a total of four accesses to the disk drives. This is realized by combining the read-modify-write operation of updating one or more sectors in an ISF cluster with the read-modify-write operation associated with updating one or more sectors in a parity-based array system, such as a RAID-5 system.

Abstract: A RAID-1 system achieves sparing by allocating 1/(2N−1) of each storage device as a spare region, in a mirrored RAID-1 system having N pair of mated devices. The remaining portion of each device is partitioned into (2N−2) data partitions. If a device fails, the contents of its mate are copied into the spare regions of the other devices. This preserves fault tolerance even if a second device subsequently fails.

Abstract: A system and associated method efficiently complete write commands in an ISF disk drive/RAID system with minimal disk accesses to the underlying disk drives. The system updates data in a parity-based disk array system by receiving a write command to write new data. The present system minimizes the number of disk accesses. The present system completes the same or comparable write commands in a total of four accesses to the disk drives. This is realized by combining the read-modify-write operation of updating one or more sectors in an ISF cluster with the read-modify-write operation associated with updating one or more sectors in a parity-based array system, such as a RAID-5 system.