Patent ID: 8151347

Claim:
A method of operating a cluster of computer system nodes sharing direct read/write access to filesystems administered by at least one trusted metadata server node on storage devices connected to the computer system nodes via a storage area network, comprising: assigning a mandatory access control label as an extended attribute of each filesystem object administered by the at least one trusted metadata server node regardless of whether required by a client node creating the filesystem object, the mandatory access control label including a first indication of sensitivity and a first indication of integrity; assigning a mandatory access control label having a second indication of sensitivity and a second indication of integrity to each node having access to the filesystem object; and permitting access to the filesystem object by any client node only if the second indication of sensitivity and the second indication of integrity assigned thereto meets criteria defined by the first indication of sensitivity and the first indication of integrity in the mandatory access control label of the filesystem object; wherein if any user is permitted to modify the contents of a filesystem object, it is given a low indication of integrity; if a filesystem object can be modified by only a specified user, it is given a high indication of integrity; if a filesystem object can be viewed by anyone, it is given a low indication of sensitivity rating; if a filesystem object contains information only one user can view, it is given a high indication of sensitivity rating.