Fan speed control of rack devices where sum of device airflows is greater than maximum airflow of rack

A system comprising:

• a rack having a maximum airflow associated with a cooling component for the rack;
• a plurality of computing devices installed within the rack, the computing devices having fan speeds governing airflows through the computing devices, each computing devices to individually measure and transmit a current airflow therethrough;
• and
• a component, other than the cooling component, to calculate a sum of the current airflows through the computing devices from the current airflows individually measured through the computing devices, to choose one or more selected computing devices of the plurality of computing devices responsive to calculating that the sum of the current airflows is greater than the maximum airflows associated with the cooling component for the rack, as the computing devices that have current fan speeds less than maximum fan speeds at which the fans of the computing devices are operable, and to decrease the fan speeds of the selected computing devices so that the fans of the computing devices do not together exhaust more air into the rack than the cooling component can exhaust out of the rack,
• wherein each computing device, as a given computing device, has a fan to exhaust heat generated within the given computing device into the rack in which the given computing device is installed,
• wherein the cooling component for the rack is to exhaust the heat exhausted by the fans of the computing devices into the rack from the rack to outside the rack, the maximum airflow associated with the cooling component being a maximum flow of air that the cooling component is able to remove from the rack,
• wherein the maximum airflow associated with the cooling component is less than a sum of a maximum device airflow associated with each computing device individually,
• and wherein the selected computing devices do not immediately throttle one or more of processor instruction execution frequency, hard disk drive platter rotation rate, or memory access frequency, but are now configured to throttle the one or more of processor instruction execution frequency, hard disk drive platter rotation rate, or memory access frequency at a future point of time.

A computing device comprising:

• a housing to be installed within a rack along with one or more other computing devices, the rack having a maximum airflow associated with a cooling component for the rack;
• hardware within the housing;
• and,
• a component, other than the cooling component, implemented by the hardware to individually measure and transmit a current airflow through the computing device, and to decrease a fan speed of the computing device where the computing device has been selected for fan speed reduction and has a current fan speed less than a maximum fan speed at which a fan of the computing device is operable to exhaust heat generated within the computing device into the rack, responsive to a calculation that a sum of the current airflow through the computing device and individually measured current airflows through the other computing devices is greater than the maximum airflow, so that the computing device and the other computing device do not together exhaust more air into the rack than the cooling component can exhaust out of the rack,
• wherein each of the other computing devices, as a given computing device, has a fan to exhaust heat generated within the given computing device into the rack in which the given computing device is installed,
• wherein the cooling component for the rack is to exhaust the heat exhausted by the fans of the computing device and the other computing devices into the rack from the rack to outside the rack, the maximum airflow associated with the cooling component being a maximum flow of air that the cooling component is able to remove from the rack,
• wherein the fan speed governs airflow through the computing device,
• wherein the maximum airflow associated with the cooling component is less than a sum of a maximum device airflow associated with each computing device individually,
• and wherein the computing device does not immediately throttle one or more of processor instruction execution frequency, hard disk drive platter rotation rate or memo access frequency, but is now configured to throttle the one or more of processor instruction execution frequency, hard disk drive platter rotation rate, or memory access frequency at a future point of time.

A data storage device having computer-readable code stored thereon for execution by a processor of a first computing device, the computer-readable code comprising:

• first computer-readable code to receive current airflows of a plurality of second computing devices installed within a rack from the second computing devices as individually measured at the second computing devices, the second computing devices having fan speeds governing airflows through the second computing devices, the rack having a maximum airflow associated with a cooling component for the rack;
• second computer-readable code to calculate a sum of the current airflows through the second computing devices from the current airflows measured through the second computing devices individually;
• and
• third computer-readable code to choose one or more selected computing devices of the second computing devices responsive to calculating that the sum of the current airflows is greater than the maximum airflows associated with the cooling component for the rack, as the second computing devices that have current fan speeds less than maximum fan speeds at which the fans of the second computing devices are operable to instruct each selected computing device to decrease the fan speed thereof, so that the second computing devices do not together exhaust more air into the rack than the cooling component can exhaust out of the rack,
• wherein each second computing device, as a given computing device, has a fan to exhaust heat generated within the given computing device into the rack in which the given computing device is installed,
• wherein the cooling component for the rack is to exhaust the heat exhausted by the fans of the second computing devices into the rack from the rack to outside the rack, the maximum airflow associated with the cooling component being a maximum flow of air that the cooling component is able to remove from the rack,
• wherein the maximum airflow associated with the cooling component is less than a sum of a maximum device airflow associated with each second computing device individually,
• and wherein the selected computing devices do not immediately throttle one or more of processor instruction execution frequency, hard disk drive platter rotation rate, or memo access frequency, but are now configured to throttle the one or more of processor instruction execution frequency, hard disk drive platter rotation rate, or memory access frequency at a future point of time.