05893140 is referenced by 208 patents and cites 60 patents.

A conventional network file server has a file system that permits file attributes and file data to be written in any order. The conventional network file server may also support an asynchronous write protocol, in which file attributes and file data need not be written to disk storage until a client sends a commit request. This asynchronous write protocol has a data security problem if the attributes are written before the data and the server crashes before completing the writing of the data to disk storage. This security problem is solved by adding a file system cache and following a protocol that writes the attributes to storage after writing the data to storage. For example, the attributes and data are stored in the file system cache and are not written down to storage until receipt of a commit request. When the commit request is received, the data is sent first from the file system cache to storage. Then the attributes are sent from the file system cache to storage. Then the file server acknowledges completion of the commit operation. In a preferred embodiment, storage is provided by an integrated cached disk array (ICDA) having a buffer cache and an array of disk drives, and the file system cache is distributed in a plurality of data mover computers interfaced to the ICDA. The addition of the file system cache to solve the security problem also reduces the burden on the buffer cache in the ICDA.

Title
File server having a file system cache and protocol for truly safe asynchronous writes
Application Number
8/747631
Publication Number
5893140
Application Date
November 13, 1996
Publication Date
April 6, 1999
Inventor
Percy Tzelnic
Concord
MA, US
Betti Porat
Newtonville
MA, US
Uday Gupta
Westford
MA, US
Uresh K Vahalia
Newton
MA, US
Agent
Arnold White & Durkee
Assignee
EMC Corporation
MA, US
IPC
H04N 7/14
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