Patent ID: 7370142

Claim:
A network storage system for receiving a file access request from a client via a network and accessing a disk device, comprising: a request receiving means; a file system control means; and a command controller, the command controller including an allocation information table, a command classification means, and a command selection means, wherein the request receiving means accepts file access requests from a client, the file system control means converts the file access requests accepted by the request receiving means into disk access commands that can be interpreted in the disk device, and the command controller controls delivery of the disk access command to the disk device, wherein the allocation information table registers allocation information managed by the file system control means, the allocation information including command classification identifiers, each of the command classification identifiers identifying each class of disk access commands, and ranges of logical block addresses, each of the ranges being allocated for each of file groups to be accessed by disk access commands belonging to a corresponding class of the disk access commands, the command classification means specifies a class of each of the disk access commands transferred from the file system control means by comparing an access target address of the each of the transferred disk access commands with the ranges of logical block addresses registered in the allocation information table and stores the each of the disk access commands in each buffer provided individually for each class to form classified queues of the disk access commands, and the command selection means consecutively repeats selecting a queue from the classified queues of the disk access commands and delivers a corresponding disk access command located at a head of the selected queue to the disk device.