Dynamic data access pattern detection in a block data storage device

A block data storage device configured to retrieve user data to a host device in response to read commands issued by the host device, comprising:

• a data buffer;
• a data recording medium on which the user data are stored in a number of data sectors having associated data sector addresses;
• a data transducing head adjacent the data recording medium and which accesses the data sectors;
• and
• means for dynamically switching from a nonlocal mode of operation to a local mode of operation in relation to a detected access pattern in read commands issued by the host, wherein during the local mode of operation nonrequested user data are retrieved from the recording medium and placed into the buffer in anticipation of a future request for the nonrequested user data, and wherein during the nonlocal mode of operation said nonrequested user data are not retrieved from the recording medium and are not placed into the buffer.

A method for transferring data between a host device and a block data storage device having a first memory space and a second memory space, the second memory space storing user data in a plurality of data sectors each having an associated data sector address, the method comprising:

• providing a most recent read command to request user data from a selected data sector having a selected data sector address;
• comparing the selected data sector address to data sector addresses associated with a plurality of recent read commands;
• and
• switching from a nonlocal mode of operation to a local mode of operation when the selected data sector address overlaps at least one of the data sector addresses associated with the plurality of recent read commands, wherein during the local mode of operation, nonrequested user data are retrieved from the second memory space and placed into the first memory space in anticipation of a future request for the nonrequested user data, and wherein during the nonlocal mode of operation said nonrequested user data are not retrieved from the second memory space and are not placed into the first memory space.