Tape library mirrored redundant controllers
AssigneeStorage Technology Corporation
InventorsAntonio Borrego, Steven Ochs, Don Wait
Life of this patent
Estimating the term…
Abstract
The present invention provides two redundant tape library controllers that mirror each other's function. A secondary controller can immediately take over from the primary controller if the primary unit fails or if a redundant path leading to the primary controller fails.
Claims18
A method for providing control mechanism redundancy, the method comprising:
- initiating a first control unit, wherein the first control unit executes input/output (I/O) for at least one robotic device;
- initiating a second control unit, wherein the second control unit is subordinate to the first control unit and monitors I/O for the robotic device;
- wherein the first and second control units operate in tandem and monitor each other's status by means of at least one communication channel between the first and second control units;
- and
- if the first control unit fails to respond to a specified number of status inquires sent by the second control unit, allowing the second control unit to assume responsibility for I/O for the robotic device.
A computer program product in a computer readable medium for use in a data processing system, for providing control mechanism redundancy, the computer program product comprising:
- instructions for initiating a first control unit, wherein the first control unit executes input/output (I/O) for at least one robotic device;
- instructions for initiating a second control unit, wherein the second control unit is subordinate to the first control unit and monitors I/O for the robotic device;
- wherein the first and second control units operate in tandem and monitor each other's status by means of at least one communication channel between the first and second control units;
- and
- instructions for allowing the second control unit to assume responsibility for I/O for the robotic device if the first control unit fails to respond to a specified number of status inquires sent by the second control unit.
A system for providing control mechanism redundancy, the system comprising:
- a first control unit, wherein the first control unit executes input/output (I/O) for at least one robotic device;
- a second control unit, wherein the second control unit is subordinate to the first control unit and monitors I/O for the robotic device;
- wherein the first and second control units operate in tandem;
- at least one communication channel between the first and second control units, whereby the first and second control units monitor each other's status;
- and
- a switchover mechanism which allows the second control unit to assume responsibility for I/O for the robotic device if the first control unit fails to respond to a specified number of status inquires sent by the second control unit.
Dependencies are inferred from the claim text.