Video circulation storage method and system and computer

The invention provides a video circulation storage method and system and a computer, and the method comprises the steps: dividing a disk into a plurality of logical volumes, and endowing each logical volume with a unique volume number; based on the plurality of logical volumes, constructing an index directory comprising stock recording numbers, metadata and stock serial numbers; acquiring updated video data, extracting a current recording number of the updated video data, and determining a storage path of the updated video data through the current recording number, the stock recording number, the stock serial number and the volume number so as to determine a distribution volume from the plurality of logical volumes; and obtaining an update serial number, writing update video data in the distribution volume, and updating the index directory based on the update serial number and the update video data. By setting the index directory, the stock serial number and the update serial number, IO operation of the disk