PRIMECLUSTER Global File Services Configuration and Administration Guide 4.2 (Solaris(TM) Operating Environment)

12.10.7 Notes on performance of read access for EOF

In the GFS Shared File System, the read of EOF is compared with processing in the read of the other part than a file, and processing performance becomes bad.

When the read of EOF is performed in file operation with the GFS Shared File System, confirms whether the file record lock exists from the other node for same part of the file.

At this time, communicates between AC/MDS. This processing is done with read of other part in the file, but on the part except EOF, the file record lock state can be memorized with AC side.

But in exclusive control between shared nodes, cache cannot do file record lock information besides the node that it is written in, and maintain authority on a block including EOF (a management block by 8 kilobytes unit).

On this account becomes conspicuous increase between processing time by read about EOF is done, and a communication for confirmation becomes necessary, and it is compared with ufs, and an unnecessary confirmation cost suffers, and executing it repeatedly.