Method and apparatus for suspending communication with a hard disk drive in order to transfer data relating to the hard disk drive

An apparatus for communicating information relating to a disk drive through a bus in use between the disk drive and a host adapter, comprising:

• a plurality of switches interconnecting the disk drive to the bus;
• a processing device in communication with the bus and the plurality of switches, wherein the processing device provides a shadow register having an address that is the address of a register of the disk drive and wherein the processing device is operative to:
• intercept a reset signal through the bus from the host adapter,
• trigger the plurality of switches to isolate the disk drive from the bus in response to the intercept of the reset signal;
• share information relating to the disk drive with the host adapter through interaction of the shadow register with the bus while the disk drive is isolated from the bus;
• and
• utilize a local communication link with the isolated disk drive to instruct the isolated disk drive to perform at least one activity in response to receiving a control signal from the host adapter.

A computer system comprising:

• a first data bus in communication with a central processing unit;
• a second data bus in communication with a disk drive;
• a host adapter that passes data between the first bus and the second bus including a reset signal in response to a command from the central processing unit;
• a gateway in communication with the second bus and the disk drive, the gateway comprising:
• a plurality of switches interconnecting the disk drive to the second bus;
• a processing device that provides a shadow register having an address that is the address of a register of the disk drive, wherein the processing device is in communication with the second bus and the plurality of switches and is configured to:
• intercept a reset signal through the second bus from the host adapter,
• in response to intercepting the reset signal, trigger the plurality of switches to communicatively isolate the disk drive from the second bus without physically disconnecting the disk drive from the computer system;
• receive a control signal from the host adapter directing at least one activity of the disk drive;
• and
• utilize a local communication link with the isolated disk drive to instruct the isolated disk drive to perform the at least one activity in response to receiving the control signal from the host adapter.

A method of communicating information relating to a disk drive through a bus in use between the disk drive and a host, comprising:

• detecting at the host that a communication of information relating to the disk drive should occur;
• asserting a reset from the host to isolate the disk drive from the bus and to interconnect a shadow register with the bus, wherein the shadow register has an address that is an address of a register of the disk drive;
• and
• communicating at the host information relating to the disk drive with the shadow register, wherein communicating information relating to the disk drive with the shadow register comprises providing control signals directing at least one activity of the isolated disk drive.