Access patterns

GPFS attempts to recognize the pattern of accesses (such as strided sequential access) that an application makes to an open file. If GPFS recognizes the access pattern, it will optimize its own behavior.

For example, GPFS can recognize sequential reads and will retrieve file blocks before they are required by the application. However, in some cases GPFS does not recognize the access pattern of the application or cannot optimize its data transfers. In these situations, you may improve GPFS performance if the application explicitly discloses aspects of its access pattern to GPFS through the gpfs_fcntl() library call.