gtpm1m3h | TPF V4R1 Migration Guide: 3.1 to 4.1 |
This section discusses:
When the fault-rate threshold for channel failures is reached, the TPF system cycles down to 1052 state and requires a hard IPL to go above 1052 state again.
In the TPF 3.1 system, there were two fault-rate thresholds for processor errors, one for catastrophic processor failures and another for non-catastrophic processor failures. In the TPF 4.1 system, there is only a threshold for catastrophic processor failures. When the fault-rate threshold for catastrophic processor failures is reached, the TPF system requires a hard IPL before restarting, and issues a message recommending that the operator switch to the backup processing complex.
You can change the fault-rate threshold for both channel and processor failures. See Changing the Fault-Rate Threshold for more information.
In the TPF 4.1 system, to minimize the impact to resources, the TPF system issues fewer operator messages detailing channel and processor failures. If you have operating procedures keyed to messages from the channel check and machine check handlers, you must adjust your procedures to take into account the revised set of messages.
If an SVP damage, warning, or degradation is reported in a non-catastrophic context, the TPF 4.1 system cycles down to 1052 state and requires a hard IPL to go above 1052 state again.
In a catastrophic context, the TPF 4.1 system requires a hard IPL before restarting and issues a message recommending that the operator switch to the backup processing complex.
In the TPF 3.1 system, you could enable or disable system recovery messages using the RECORD and QUIET parameters for the ZCMKH command. In the TPF 4.1 system, the ZCMKH command is no longer supported. The TPF system runs with these messages disabled (QUIET).
In the TPF 4.1 system, the operator must issue an IPL CLEAR to recover fully from a DEADxx disabled wait state. In such a disabled wait state, there may be a storage error that the machine check handler was unable to circumvent, in which case the page and segment tables must be rebuilt. The IPL CLEAR forces these tables to be rebuilt.