Some embodiments of the present invention provide a system that stores telemetry data from a computer system. The system includes a first buffer, a second buffer, and a third buffer. During operation, the system periodically obtains the telemetry data from the computer system and stores the telemetry data in the first buffer, second buffer, and third buffer. The system also compresses the telemetry data in the first and second buffers. To compress the data, the system creates a first set of summary statistics from the telemetry data in the first buffer and the second buffer and stores the first set of summary statistics in the first buffer, which becomes a historical data buffer.