Apparatus, system, and method for detecting device types of storage devices

1. An apparatus comprising:

a drive-plane board comprising a plurality of connectors for coupling a plurality of storage devices to a power supply;

for each connector in the plurality of connectors, at least one circuit that:

is electrically coupled to the power supply;

comprises a resistor coupled between the power supply and ground;

comprises a switch connected in series between the resistor and ground;

when a storage device is connected to the power supply, outputs a signal that indicates, based on whether the switch is open or closed, a device type of the storage device; and

is electrically coupled to at least one physical processing device that:

detects the signal that is output by the circuit when the storage device is connected to the power supply;

determines, based at least in part on the signal output by the circuit, whether the device type of the storage device comprises a Serial Attached Small Computer System Interface (SAS) hard drive or a Serial Advanced Technology Attachment (SATA) hard drive; and

directs the power supply to supply power to the storage device in accordance with the device type of the storage device.

2. The apparatus of claim 1 , wherein

the switch is connected in series between the resistor and ground such that:

the circuit outputs a logical high when the switch is open; and

the circuit outputs a logical low when the switch is closed.

3. The apparatus of claim 2 , wherein the storage device comprises a section that:

makes physical contact with the switch; and

when the section includes an electrically-conductive material, causes the switch to close.

4. The apparatus of claim 3 , wherein the electrically-conductive material comprises a connector between at least two outputs of the storage device.

5. The apparatus of claim 4 , wherein:

the storage device represents the SAS hard drive;

the SAS hard drive includes the connector; and

when the SAS hard drive connects to the power supply, the switch closes.

6. The apparatus of claim 5 , wherein the physical processing device directs the power supply to immediately begin supplying power to a motor of the SAS hard drive upon detecting that the SAS hard drive is connected to the power supply.

7. The apparatus of claim 4 , wherein:

the storage device represents the SATA hard drive;

the SATA hard drive does not include the connector; and

when the SATA hard drive is connected to the power supply, the switch is open.

8. The apparatus of claim 7 , wherein the physical processing device directs the power supply to wait for a command before supplying power to a motor within the SATA hard drive.

9. The apparatus of claim 1 , wherein, for each connector in the plurality of connectors, the circuit is incorporated into the connector.

10. A system comprising:

a drive-plane board dimensioned to be installed in a data-center rack, wherein the drive-plane board comprises a plurality of connectors for coupling a plurality of storage devices to a power supply;

for each connector in the plurality of connectors:

at least one circuit that:

is electrically coupled to a power supply;

when a hard drive is connected to the power supply;

comprises a resistor coupled between the power supply and ground; and

comprises a switch connected in series between the resistor and ground; and

at least one physical processing device that:

is electrically coupled to the circuit;

detects the signal that is output by the circuit when the hard drive is connected to the power supply;

determines, based at least in part on a signal that is output by the circuit and that indicates, based on whether the switch is open or closed, whether a device type of the hard drive comprises a Serial Attached Small Computer System Interface (SAS) hard drive or a Serial Advanced Technology Attachment (SATA) hard drive; and

directs the power supply to supply power to the hard drive in accordance with the device type of the hard drive.

11. The system of claim 10 , wherein

the switch is connected in series between the resistor and ground such that:

the circuit outputs a logical high when the switch is open; and

the circuit outputs a logical low when the switch is closed.

12. The system of claim 11 , wherein the hard drive comprises a section that:

makes physical contact with the switch; and

when the section includes an electrically-conductive material, causes the switch to close.

13. The system of claim 12 , wherein the electrically-conductive material comprises a connector between at least two outputs of the hard drive.

14. The system of claim 13 , wherein:

the hard drive represents the SAS hard drive;

the SAS hard drive includes the connector; and

when the SAS hard drive connects to the power supply, the switch closes.

15. The system of claim 14 , wherein the physical processing device directs the power supply to immediately begin supplying power to a motor of the SAS hard drive upon detecting that the SAS hard drive is connected to the power supply.

16. The system of claim 13 , wherein:

the hard drive represents the SATA hard drive;

the SATA hard drive does not include the connector; and

when the SATA hard drive is connected to the power supply, the switch is open.

17. The system of claim 16 , wherein the physical processing device directs the power supply to wait for a command before supplying power to a motor within the SATA hard drive.

18. The system of claim 10 , wherein for each connector in the plurality of connectors, the circuit is incorporated into the connector.

19. A method comprising:

electrically coupling an array of storage devices to a power supply that supplies power to the storage devices;

for each storage device in the array of storage devices:

electrically coupling, to the power supply, a circuit comprising

a resistor coupled between the power supply and ground; and

a switch connected in series between the resistor and ground; and

electrically coupling, to the circuit, a physical processing device that:

determines, based at least in part on a signal that is output by the circuit and that indicates, based on whether the switch is open or closed, whether a device type of the storage device comprises a Serial Attached Small Computer System Interface (SAS) hard drive or a Serial Advanced Technology Attachment (SATA) hard drive; and

directs the power supply to supply power to the storage device in accordance with the device type of the storage device.

20. The method of claim 19 , wherein electrically coupling the circuit to the power supply comprises:

coupling the resistor between the power supply and ground; and

connecting the switch in series between the resistor and ground such that:

the circuit outputs a logical high when the switch is open; and

the circuit outputs a logical low when the switch is closed.