PIOPAGES is a system parameter that specifies the size of the process I/O segment, which holds data structures and buffer pool space for RMS to use when it handles I/O that involves process-permanent files. Once PIOPAGES is reset in SYSGEN, any new process receives the changed value. Beginning with OpenVMS Version 7.2, the default value has been raised to 575. The setting has been raised to accommodate the increased demands for process-permanent memory that result from changes made to RMS file-naming parsing in Version 7.2. This special parameter is use by VSI and is subject to change. Do not change this parameter unless VSI recommends that you do so. PIOPAGES is an AUTOGEN and DYNAMIC parameter.