A cloud black box (CBB) subsystem in a cloud computing infrastructure includes CBB storage and computer processing circuitry executing a CBB application having first and second operating modes. In a depository mode information messages are continually received from hardware computing devices during normal operation and device information from the messages is stored into the CBB storage. The information messages are generated by CBB agents executing on the hardware computing devices, which continually collect the device information and generate the information messages according to a common information transfer protocol. In a retrieval mode, device information in the CBB storage is provided to a requestor such as a data analysis application, which may be part of or external to the CBB subsystem. The CBB subsystem operates independently and remains available upon failure of hardware or software components in the cloud infrastructure, providing a centralized source of information for diagnosis or other analysis.