Patent ID: 7130855

Claim:
A method for delaying asynchronous writes in a distributed file system of a computing system to which a unique identifier is assigned, comprising: said computing system buffering a page of dirty data with the unique identifier upon writing to a server; said computing system changing the unique identifier to create a current unique identifier that is assigned to the distributed file system upon a failure of the server; said computing system comparing the buffered unique identifier with the current unique identifier when the page is requested while the page is in a written state; said computing system handling the request responsive to the comparison by storing the buffered written page to disk storage if the buffered unique identifier differs from the current unique identifier or performing a file sync operation if the buffered unique identifier matches the current unique identifier; and said computing system maintaining cache consistency by issuing an exclusive mode token from the server to a client to permit the client to dirty the page, issuing a shared mode token from the server to the client to permit the client to use, but not dirty, the page, and revoking the exclusive mode token before issuing the shared mode token.