Western Digital Corporation

Lsi Corporation

Xiotech Corporation

Western Digital Technologies, Inc.

Jeffrey L Williams

Daniel John Sokolov

Timothy W Swatosh

Michael Scott Hicken

Steven M Howe

Randal Rysavy

Chun Sei Tsai

Gregory B Thelin

Carl E Forhan

Jonathan M Henze

Jeffrey Munsil

Scott McClure

Jillian D Passioukov

Bryan Holty

Lyle Bergman

Dave Ebsen

A write command is received to write data in a target zone including one or more tracks and it is determined whether a data structure is stored in a memory for counting writes performed in a track of the target zone. If such a data structure is not stored in the memory, at least one Low Repeat Write (LRW) data structure is created for the target zone to count writes in sectors of respective tracks of the target zone since creation of the at least one LRW data structure. In another aspect, a write count for a segment is incremented in a data structure for a track to account for a write in the segment. A current overall Track Interference (TI) write count for the target zone is incremented if the incremented segment write count is the highest write count among respective segment write counts in the data structure.

Dynamic track interference write counting for magnetic disks

Aspects of the disclosure pertain to a system and method for key wrapping via a storage system to allow secure access to media of the system by multiple authorities with modifiable permissions. The keys used to encrypt ranges of the drive are not stored in plaintext and are recoverable using the credentials of an administrator or user with access to that particular range. An outside attacker cannot recover these keys and a malicious user can only recover the keys to the ranges that user is allowed to access. This is maintained while allowing administrators to modify permissions at any time and, while allowing both administrators and users to change their credentials at any time.

System and method for key wrapping to allow secure access to media by multiple authorities with modifiable permissions

Described embodiments provide for authenticating a user request for access to at least a portion of an encrypted storage device. First, the request for access to at least a portion of the encrypted storage device is received. The request includes a plaintext password. A hash module generates a hashed version of the received plaintext password based on an authentication hash key. A hashed value of the generated plaintext password is retrieved from a key storage. A hash comparator compares the hashed version of the received plaintext password with the retrieved hashed value of the generated plaintext password. If the hashed version of the received plaintext password and the retrieved hashed value of the generated plaintext password are equal, the user is authenticated for access to at least a portion of the encrypted storage device. Otherwise, the user is denied access to the encrypted storage device.

Interlocking plain text passwords to data encryption keys

Described embodiments provide a host subsystem that generates a host context corresponding to a received host data transfer request. A programmable sequencer generates one or more sequencer contexts based on the host context. Each of the sequencer contexts corresponds to at least part of the host data transfer request. The sequencer contexts are provided to a buffer subsystem of the media controller. For host read requests, the buffer subsystem retrieves the data associated with the sequencer contexts of the read request from a corresponding buffer or a storage media and transmits the data associated with the sequencer contexts to the host device. For host write requests, the buffer subsystem receives the data associated with the host context from the host device and stores the data associated with the sequencer contexts of the write request to a corresponding buffer or the storage media.

Processing host transfer requests for direct block access storage devices

Described embodiments provide encryption/decryption of data transferred between a media controller and a storage device. The media controller provides encryption/decryption based on a root key (RK). Storage in a one-time programmable (OTP) memory is provided as a plurality of un-burned slots. The OTP memory is initially provided without the RK, which is generated with a random number generator. A control module performs the steps of i) burning the RK to an initial slot of the OTP memory, and ii) validating the burned RK (bRK) stored at the initial slot based on a comparison of the RK and the burned RK. If the control module validates the burned RK, the burned RK is employed by the media controller. Otherwise, one or more subsequent slots of the OTP memory are burned with the RK until the control module validates the corresponding burned RK.

Saving encryption keys in one-time programmable memory

A method, apparatus and program storage device for providing control to a networked storage architecture is disclosed. A networked storage device is provided. Controllers are coupled to the at least one networked storage device for controlling input/output operations of the networked storage device. The networked storage device includes a file system for storing data provided by a first of the controllers for retrieval by the other controllers.

Method, apparatus and program storage device for providing control to a networked storage architecture

A method, apparatus and program storage device for providing intelligent rebuild order selection is a storage array is disclosed. The interrelationship of the data on the drives to be rebuilt and the remaining drives in the system is examined. A relative score for a rebuild record to be rebuilt is based upon the manner in which the RAID data is placed on the other drives. The rebuild record with the highest relative risk is identified as the rebuild record to be rebuilt next.

Method, apparatus and program storage device for providing intelligent rebuild order selection

The present invention provides a disk drive system employing a method of analyzing disk drive failure wherein a disk drive target controller is logically connected to an initiator on a SCSI bus. The method includes storing SCSI bus state information upon the receipt of a SCSI bus reset condition. SCSI bus state information is maintained, wherein the SCSI bus state information corresponds to the logical connection between the initiator and the disk drive target controller on the SCSI bus. A SCSI bus reset condition is detected. The maintained SCSI bus state information is stored upon detection of the SCSI bus reset condition. Actions are preformed to reset devices connected to the SCSI bus, including resetting the disk drive target controller. The SCSI bus state information can be subsequently analyzed to aid in determining the cause of the SCSI bus reset condition.

Disk drive method of determining SCSI bus state information after a SCSI bus reset condition

A command queuing engine in a target controller ASIC automatically detects sequential commands received from an initiator and generates a linked list of data transfer descriptors for the sequential commands. The data transfer descriptors are automatically processed by the command queuing engine to reduce command overhead from interrupt processing by a microprocessor in the target controller, thereby improving the performance of the target controller.

Controller with automatic generation of linked list of data transfer descriptors for sequential commands, with linked list being used for execution of sequential data transfers

A method for selecting a next command to execute from a set of SCSI commands where the commands are gracefully aged and performance of a disk drive is improved. An execution threshold age, a pool threshold age, and an age threshold age are used to determine what command is executed next. A mechanical time delay is calculated for a command based on the time required to position the read/write head over the data location requested in each command. A command age is calculated based on a current time and the time the command was received from the host. The command age is checked against the execution threshold age and pool threshold age. Any commands that have aged beyond the execution threshold age are executed. If the oldest command has aged beyond the age threshold age, then any command that has both aged beyond the pool threshold age and has the smallest mechanical time delay is executed, otherwise the command with the smallest mechanical time delay is executed. Alternatively, a time stamp of the oldest command is compared against an age threshold to determine if all or some of the commands are in the pool of commands. If there are no commands that have aged beyond the age threshold, then the command that has the smallest mechanical time delay is executed first.

Disk drive with adaptive pooling for command reordering

The disk drive provides a method of adaptively managing a cache segment divided into chunks by defining an unavailable data type to be stored in an element of a chunk array which indicates that the chunk is not available, and defining an available data type to be stored in an element of the chunk array that indicates the chunk is available and that indicates the number of consecutive chunks that are available. The disk drive also computes a number of chunks needed to fit the request length and scans the chunk array to find a first available element whose available data type meets a predetermined criteria for the number of chunks needed to fit the request length.

Method for memory allocation in a disk drive employing a chunk array and

A magnetic disk drive with a caching system includes an intelligent interface to communicate with a host, a magnetic disk and a cache memory to buffer data transferred to and from the host. The caching system maximizes drive performance based on past access history. The caching system alters execution of commands by coalescing commands or executing internal commands in parallel. The caching system anticipates data requests by using a prefetch to store data that may be requested. The caching system divides the cache memory into segments to store multiple streams of data. The number of segments may be continuously adapted according to the types of access to maximize performance by maintaining a segment for each sequential stream of data. The caching system uses a dynamic priority list to determine segments to maintain and discard. Each segment is monitored to determine access types such as sequential, random, and repeating. The access type determines the amount of data to prefetch and to save, including a minimum and maximum prefetch. The caching system may prescan the cache memory during prefetch to alter the prefetch amount in response to a command request. The caching system may wait for a cache memory access that has not yet occurred. An initiator changes the caching parameters though a mode page.

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Rochester, MN, United States of America

Jeffrey L Williams