Computer system cluster data access authorization checking method and system

A computer system cluster data access authorization checking system for use with an access control interface coupled between a data storage unit and a computer system cluster having multiple computer units for providing a data access authorization checking procedure for checking whether an access command received by the access control interface from one of the computer units in the computer system cluster is authorized to gain access to the data storage unit;

• the computer system cluster data access authorization checking system comprising:
• an access authorization database module, which is used to store a access authorization database in the form of a linked list of main cells with each main cell being bifurcated to an associated linked list of branch cells, where the main cells are each used to store a codename that represents each authorized computer unit in the computer system cluster in a sequenced order, and the branch cells associated with each main cell are used to store the mapping relationships of logical units of the associated computer unit to authorized volumes in the data storage unit;
• an access command acquiring module, which is capable of acquiring each access command received by the access control interface from any one of the computer units in the computer system cluster, wherein each access command contains a codename that represents the computer unit that issues the access command and a logical unit number that represents the logical unit of the computer unit where data is to be accessed;
• an access command comparison module, which is capable of comparing the codename contained in the access command acquired by the access command acquiring module sequentially against the data stored in the linked list of main cells;
• if the codename in the access command is matched to a certain main cell, the access command comparison module then compares the logical unit number contained in the access command against the data stored in the bifurcated linked list of branch cells to find the corresponding volume in the data storage unit, and then issues an access-enabling message to the access control interface;
• and
• if no match is found, the access command comparison module issues an access-inhibiting message to the access control interface.