Seagate Technology Incorporated

Jeetandra Kella

Jun Cai

Brian Thomas Edgar

ChuanPeng Ong

Mark A Gaertner

Harry Tiotantra

William Erik Anderson

Nino Wicaksono

Muhammad Jawad Alam Wahla

Xu Huang

JianZhong Zhang

Syed Yasir Abbas

Wajid Ali

Xin Li

Li Xin

Thaik Thaik Aung

AndiSumaryo Sutiawan

Described are systems, devices and methods for regulating speculative reading in a hard disk drive that has a read reliability budget. Regulating speculative reading under a read reliability budget involves selecting an amount of read look ahead (RLA) in response to determining whether or not a read rate exceeds the read reliability budget. When the read rate is lower than the read reliability budget, a full RLA amount can be used, thus ensuring high performance. When the read rate exceeds the read reliability budget, the RLA amount can be adjusted down while maintaining performance at acceptable levels. Adjustments to RLA may be made at periodic intervals, and in response to whether the workload is more sequential or more random.

Speculative read regulation in hard disk drives having read reliability budgets

Systems and methods are disclosed for resource allocation for multi-actuator systems. In some examples, a data storage device can include two or more independently moveable voice coil motor (VCM) actuators where the resources of the system to operate the VCM actuators are divided. The disclosure here describes methods to allocate or re-allocate the divided resources, such as unused resources, to a VCM actuator that has a need for more resources. The methods and systems herein can also be applied to other actuator systems.

Resource allocation for multi-actuator storage device

Apparatus and method for managing data objects in a distributed data storage system, such as a cloud computing environment. In some embodiments, a data object is encrypted using a user encryption key to generate ciphertext. A first hash function is applied to the ciphertext and an audit encryption key to generate a first hash value. An audit value is formed by combining the ciphertext and the first hash value, and the audit value is locally encrypted and stored to non-volatile memory (NVM) of each of a plurality of storage nodes. An audit process is performed to confirm each of the encrypted replicas store identical copies of the ciphertext. This is carried out by decrypting the ciphertext and applying a second hash function to the ciphertext and the audit encryption key by each storage node to form a plurality of second hash values which are then compared by an audit processor.

Secure audit scheme in a distributed data storage system

Apparatus and method for data security in a data storage environment. In some embodiments, input data from a host is received into a buffer memory. Data compression is applied to the input data to provide compressed data. Encryption is applied to the compressed data to generate encrypted data, and the encrypted data are stored in a main memory of a data storage device. A system parameter value associated with the storage of the encrypted data is generated and stored in a memory, such as the main memory of the storage device. The system parameter value may include information relating to the compression of the data. A trusted relationship is established to authenticate the host responsive to a request for the updated system parameter value. The system parameter value is transferred to the host responsive to the established trusted relationship.

Securing information relating to data compression and encryption in a storage device

Systems and methods are disclosed for a seeding mechanism for error detection codes. An error detection code may be generated using specifically modified seed input and stored to data sectors not containing valid data. A data storage device may determine if read attempts are directed to an invalid sector by analysis of the stored error detection code. In some embodiments, an apparatus may determine a first error detection code stored to a target data storage sector does not match a second error detection code calculated for the target data storage sector, compare the first error detection code to a modified error code value to determine whether the target data storage sector contains valid data, and return an indication that the target data storage sector does not contain valid data when the error detection code matches the modified error code value.

Seeding mechanism for error detection codes

A device includes one or more data storage media having a main storage area, and includes a non-volatile cache memory and a controller. The controller stores a plurality of data packets into a plurality of physical locations in the main storage area. Each of the data packets is associated with a different logical block address (LBA), and each of the physical locations is associated with a different physical location address (PLA). The controller generates mapping information that links the different LBAs to the different PLAs. Upon detecting a soft error when reading a data packet stored in a physical location, the controller relocates the data packet associated with the soft error to a physical location of the non-volatile cache memory. The controller also marks the physical location as a suspect location. The controller updates the mapping information to reflect the relocation of the data packet associated with the soft error.

Data reallocation upon detection of errors

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Singapore, Singapore

Jeetandra Kella