| 
|
Topic: power fail recovery
topics >
computer science >
database security
Topic:
error safe systems
Topic:
safety critical systems
Topic:
operating system security
Topic:
process control systems
Summary
All computer systems should recover gracefully from a power failure. Process control systems should provide automatic full recovery. Non-volatile memory, such as core, EAROM memory, or battery backup allows full state save for latter recovery. Automatic mass storage reload allows system re-initialization on restart. This capability may also be initialized on soft system failure. Some system state is often lost on power fail and database integrity may be suspect. The restart task should clean up the system and its databases. Then, active tasks can be continued, restarted, or terminated. Since a power fail may happen at any time, careful design is needed for successful power fail recovery. An uninterruptible power supply (UPS) allows the system to shut down in a safe state. (cbb 5/80)
Subtopic: non-volatile memory
Quote: a control system must have power-fail/auto-restart; by sensing power-on or via a watchdog system [»instrumentcontrol] Quote: a task has three options on power-fail restart; restart at specified step, resume execution, or terminate [»weavAC_1978]
Subtopic: uninteruptible power supply
QuoteRef: controleng ;;6/77 11 Cincinnati Milacron Maximiser PC for $1413 first use of "non-volatile (EAROM) R/W memory which doesn't require battery backup and can be loaded with a new program via cassette in less than a minute and a half.
Subtopic: notification
Quote: implement a safe file cache with battery-backed memory [»chenPM9_1996] QuoteRef: instrumentcontrol ;;4/77 57 Boyle PW: "An inexpensive battery-powered UPS (uninterruptible power supply) using nickel-cadmium batteries will keep microprocessors functioning throughout all types of power interruptions.
QuoteRef: lampL1_1976 ;;18 [This allows one processor to go down and change some condition which flags other processors that have trouble
Topic: database security (12 items)
Topic: error safe systems (76 items)
Topic: safety critical systems (32 items)
Topic: operating system security (18 items)
Topic: process control systems
(3 items)