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9.2 The Concurrent File System (CFS)

This is the secondary storage of the iPSC/860. The nodes use the CFS for high-speed simultaneous access to secondary storage. /cfs is the default directory for CFS. You should create a directory /cfs/yourname before using the CFS. This will be your CFS directory.

Files are accessed using the standard UNIX system calls in either C or FORTRAN. A node program can access a concurrent file in one of four I/O modes.

Mode 0: Individual file pointer(IFP). This is the default mode.
Mode 1: Unsynchronized, Common file pointer(CFP).
Mode 2: Synchronized, CFP, variable length.
Mode 3: Synchronized, CFP, fixed length.

The system call setiomode() is used to set a file I/O mode, and iomode() to determine a file's current mode.