gtpg1m0iGeneral Information

System Restart

If downtime occurs, the TPF system restarts automatically or by an operator message. A copy of the fixed area of main storage, a restart program, and an IPL program are kept on file storage for restarting the system.

TPF hardware systems are usually duplicated to reduce exposure to equipment failure. The switching of equipment, other than CPCs, can involve physical switching, an operator action, or a restart. The switching of CPCs is done by the operator who manually restarts the other CPC. Backup procedures for a system with HPO are slightly different. With HPO, the number of CPCs are expanded or contracted as required by system load. Backup occurs by contracting the complex and then switching, followed by expanding the complex. TPF preserves critical application data across a downtime. This is possible because the file copy of the critical data located in main storage is updated periodically.