Abstract: Some embodiments of the present invention provide a system that generates a simulated vibration pattern in a computer subsystem. During operation, a vibration pattern is monitored at a location in the computer subsystem, wherein the vibration pattern is monitored while the computer subsystem is incorporated into the computer system and the computer system is operating. Then, the vibrations of the computer subsystem are mimicked by generating the simulated vibration pattern at the same location in the computer subsystem based on the monitored vibration pattern.

Abstract: One embodiment of the present invention provides a system that determines the complexity of a transaction between a first entity and a second entity. The system starts by determining a first probability of success for a portion of the transaction which is associated with actions of the first entity. The system then determines a second probability of success for a portion of the transaction which is associated with actions of the second entity. The system next calculates a transactional complexity for the transaction based on the first probability of success and the second probability of success.

Abstract: One embodiment of the present invention provides a system that generates a vibration profile for a rotational device in a computer system. During operation, the system sequentially sweeps a rotation speed of a rotational device over a range of rotation speeds. While driving the rotational device at each rotation speed, the system collects a time-domain vibration signal produced by the rotational device and subsequently computes a frequency spectrum of the time-domain vibration signal. In this way, the system generates a set of frequency spectra associated with the range of rotation speeds. Next, the system combines the set of frequency spectra to generate a composite vibration profile for the rotational device.

Abstract: Some embodiments of the present invention provide an apparatus that isolates a computer system from vibrations generated by one or more fans inside the computer system. The apparatus includes a fan deck upon which the one or more fans are mounted inside the computer system, and three spring assemblies. Each spring assembly includes: a pin that extends through a clearance hole in the fan deck, wherein a first end of the pin is rigidly coupled to the computer system; a lower spring that extends between a first side of the fan deck and a lower spring mount coupled to the pin; and an upper spring that extends between a second side of the fan deck and a upper spring mount coupled to the pin.

Abstract: Some embodiments of the present invention provide a system that characterizes the performance of a disk drive at frequencies in a set of frequencies in a frequency range. First, the disk drive is vibrated at each frequency in the set of frequencies, one frequency at a time. During this process, a disk drive performance metric is monitored. Next, the performance of the disk drive is characterized by determining the parameter related to acceleration due to the vibrations for each frequency at which a disk drive performance metric degrades by a predetermined amount from a baseline.

Abstract: One embodiment of the present invention provides a system that cancels fan noise in a computer system. During operation, the system obtains a fan noise signal using a microphone. Next, the system generates a spectral pattern based on the obtained fan noise signal. The system then uses the spectral pattern to identify a corresponding cancellation spectrum in an anti-spectra library. Next, the system generates a noise-canceling signal using the cancellation spectrum. Note that the amount of computation required to cancel fan noise is reduced because generating the noise-canceling signal using the anti-spectra library requires less computation than generating the noise-canceling signal using dynamic noise-cancellation techniques.

Abstract: Some embodiments of the present invention provide a system that detects the presence of constrained motion in one or more components in a computer system. First, a vibrational spectrum of the computer system is monitored while the computer system operates. Then, the vibrational spectrum is analyzed using a pattern-recognition model to detect constrained motion in one or more components in the computer system, wherein the pattern-recognition model classifies the vibrational spectrum as indicating constrained motion or as not indicating constrained motion.

Abstract: Some embodiments of the present invention provide a system that prolongs a remaining useful life of a power supply in a computer system. First, performance parameters of the power supply are monitored. Next, the remaining useful life of the power supply is predicted based on the monitored performance parameters. Then, an operational regime of the power supply is adjusted based on the predicted remaining useful life to prolong the remaining useful life.

Abstract: Some embodiments of the present invention provide a system that controls a device that characterizes the health of a computer system power supply. During operation, a signature for the power supply is generated based on measurements of a set of performance parameters for the power supply. Then, the health of the power supply is characterized based on a comparison between the signature for the power supply and signatures for one or more other power supplies.

Abstract: Some embodiments of the present invention provide a system that generates a composite vibration profile in a frequency range for a computer system. First, a vibration spectrum in the frequency range is measured for a test computer system in each configuration in a set of configurations. Then, the composite vibration profile for the computer system is generated based on the measured vibration spectra.

Abstract: Some embodiments of the present invention provide a system that determines a center of rotation for a component in a computer system. During operation, the system measures a first acceleration of a first location on the component and a second acceleration of a second location on the component, wherein the first location and the second location are separated by a predetermined distance. Then, the system determines the center of rotation using the first acceleration, the second acceleration, and the predetermined distance.

Abstract: Some embodiments of the present invention provide a system that characterizes a response of a component in a computer system to vibrations generated by the computer system. First, the system measures the response of the component to vibrations in a frequency range while the component is located outside of the computer system. The system also measures vibrations generated by the computer system in the frequency range during operation of the computer system, wherein the vibrations are measured at a location in the computer system which is configured to receive the component. The system then characterizes the response of the component to vibrations generated by the computer system based on the measured response of the component to vibrations in the frequency range and the measured vibrations in the frequency range at the location.

Abstract: Embodiments of a system for regulating an efficiency of a power supply in a computer system are described. During operation, the system measures an output load of the power supply using one or more telemetry monitors in the computer system. Then, the system determines if an efficiency of the power supply corresponding to the measured output load is within a predetermined range that includes an optimal efficiency of the power supply. If the efficiency is outside of the predetermined range, the system performs remedial action so that the power supply operates at an adjusted efficiency that falls within the predetermined range.

Abstract: Some embodiments of the present invention provide a system that generates a simulated vibration pattern in a computer subsystem. During operation, a vibration pattern is monitored at a location in the computer subsystem, wherein the vibration pattern is monitored while the computer subsystem is incorporated into the computer system and the computer system is operating. Then, the vibrations of the computer subsystem are mimicked by generating the simulated vibration pattern at the same location in the computer subsystem based on the monitored vibration pattern.

Abstract: One embodiment of the present invention provides a system that constructs a classifier that distinguishes between different classes of data points. During operation, the system first receives a data set, which includes class-one data points and class-two data points. For each class-one data point in the data set, the system uses a separating primitive to produce a set of point-to-point separating boundaries, wherein each point-to-point separating boundary separates the class-one data point from a different class-two data point. Next, the system combines separating boundaries in the set of separating boundaries to produce a point-to-class separating boundary that separates the class-one data point from all of the class-two data points in the data set.

Abstract: Some embodiments of the present invention provide a system that includes a drive carrier for a hard disk drive (HDD) and one or more vibration control clips affixed to the drive carrier. Within this system, a mode of vibration of the HDD is modulated by contact between each of the vibration control clips and a surface within the computer system.

Abstract: Some embodiments of the present invention provide a system that characterizes a response of a device in a computer system to vibration over a frequency range. During operation, the device is vibrated at each frequency in a set of frequencies in the frequency range, wherein the device is vibrated at each frequency, one frequency at a time, until a stabilized response of the device is determined. The response of the device to vibration over the frequency range is then characterized based on information related to the stabilized response at each frequency in the set of frequencies.

Abstract: Embodiments of a mechanical device to facilitate in-situ measurements of vibration associated with a corresponding component in a computer system are described. This mechanical device includes a housing that has approximately a same mass as the component, approximately a same distribution of mass about a geometric center of the component, and approximately a same form factor as the component. Moreover, the mechanical device includes one or more vibration sensors, which are mechanically coupled to the housing, and which are configured to perform the in-situ vibration measurements.

Abstract: Some embodiments of the present invention provide a system that schedules read operations for disk drives in a set of disk drives. During operation, the system monitors a write rate for write operations to a given disk drive in the set of disk drives, wherein vibrations generated by the read operations directed to disk drives in the set of disk drives are transmitted to the given disk drive. Then, the read operations for disk drives in the set of disk drives are scheduled based on the write rate for the given disk drive, thereby limiting interference between the write operations and the vibrations generated by the read operations.

Abstract: Some embodiments of the present invention provide a system for scheduling spin-up operations for a set of hard disk drives (HDDs) in a computer system. During operation, the system determines an available power of the computer system. Next, one or more HDDs are selected from the set of HDDs to be spun-up based on the available power and the power required to spin up each HDD. Then, spin-up operations are scheduled for the selected HDDs.