Cluster power management technique

A cluster apparatus comprising:

• a plurality of hosts connected together by a cluster interconnection fabric;
• a cluster administrator connected to said plurality of hosts via said fabric, said cluster administrator comprising a cluster power manager;
• a plurality of I/O (input/output) units connected to said plurality of hosts and said cluster interconnection fabric;
• each of said hosts comprising a control element and an OS power manager and an I/O controller device driver stack;
• wherein said cluster administrator transmits a request to said control element of one of said hosts via said fabric and receives a reply therefrom via said fabric and transmits a command and wherein said control element transmits said command to said OS power manager and said I/O controller device driver stack of its host and transmits a command completion acknowledgment to said cluster power manager via said fabric.

A method of power management for a cluster comprising a plurality of hosts connected to a plurality of I/O (input/output) units via a cluster interconnection fabric, the method comprising:

• transmitting a query request from an OS (operating system) power manager in one of the hosts to an I/O (input/output) controller device driver stack and to a control element in said one host;
• forwarding said query request from said control element to a cluster power manager via said fabric;
• transmitting response to said control element from said cluster power manager via said fabric;
• forwarding said response to said OS power manager from said control element;
• transmitting command to said control element from said OS power manager via said I/O controller device driver stack;
• and
• transmitting command to cluster power manager from the control element via said fabric.

A cluster apparatus comprising:

• a plurality of hosts connected together by a cluster interconnection fabric;
• a cluster administrator connected to said plurality of hosts via said fabric, said cluster administrator comprising a cluster power manager;
• a plurality of I/O (input/output) units connected to said plurality of hosts and said cluster interconnection fabric;
• each of said hosts comprising a control element and an OS power manager and an I/O controller device driver stack;
• wherein one of said OS power managers transmits a query request to an I/O (input/output) controller device driver stack and to a control element in one of said hosts and wherein said control element forwards said query request to a cluster power Manager via said fabric which in turn transmits a response to said control element via said fabric and wherein said control element forwards said response to said OS power manager which in turn transmits a command to said control element via said I/O controller device driver stack and wherein said control element transmits a command to said cluster power manager via said fabric.

A computer program product comprising:

• a computer usable medium having a computer readable program code means embodied in said medium for power managing a cluster comprising a plurality of hosts connected to a plurality of I/O (input/output) units via a cluster interconnection fabric, said computer program product comprising:
• a computer readable program code means for causing a transmission of an O/S (operating system) independent power management request from a cluster power manager to an O/S power manager within one of the hosts via a control element in the host and the fabric;
• a computer readable program code means for causing a transmission of a reply to the request from the control element to the cluster power manager via the fabric;
• a computer readable coding means for causing a transmission of a command to the controller element from the cluster power manager via the fabric;
• a computer readable program code means for causing a transmission of the command from the control element to the O/S power manager and an I/O controller device stack in the host;
• and
• a computer readable program for causing a transmission of a command completion acknowledgment from the control element to the cluster power manager via the fabric.

A computer-readable medium that stores computer-executable instructions, the computer-executable instructions, when executed, causing a computer to:

• receive an OS (operating system) independent power management request from a cluster power manager to an OS power manager within a host via a control element in the host and a cluster interconnection fabric;
• transmit a reply to the request from the control element to the cluster power manager via the fabric;
• receive a command from the cluster power manager to the control element via the fabric;
• transmit the command from the control element to the OS power manager and an I/O controller device driver stack in the host;
• and
• transmit a command completion acknowledgment from the control element to the cluster power manager via the fabric.