Recovering a COMMDS

If you cannot access the COMMDS, you can recover from the error if you allocated a spare data set. All permanent errors that make the COMMDS unreadable require intervention. For permanent I/O errors to the COMMDS, the messages IGD041I and IGD070D appear on an operator console. Reply 'S' on the operator console and issue the following command from a system in the SMS complex:

SETSMS COMMDS(spare.commds)

One of three situations results.

If the spare COMMDS is empty it gets formatted automatically, and SMS writes the in-storage copy of the current COMMDS into the spare.commds. You then need to issue the following command on each of the remaining systems in the SMS complex:
```
SETSMS COMMDS(spare.commds)
```
If the spare COMMDS is not empty but describes an ACDS that is not currently active in the SMS complex, then SMS issues the message IGD076D. This message asks if you want to use the contents of the COMMDS and the ACDS to which it points. Reply 'C' to cause SMS to replace the contents of the spare.commds with the in-storage copy of the current COMMDS. You then need to issue the following command on each of the remaining systems in the SMS complex:
```
SETSMS COMMDS(spare.commds)
```
If the spare COMMDS is not empty but describes the ACDS that is currently active in the SMS complex, you need to issue the following command on each of the remaining systems in the SMS complex:
```
SETSMS COMMDS(spare.commds)
```

A response of 'S' to IGD070D is recommended when recovering from the current COMMDS because a response of 'C' might result in an unrecoverable error when trying to reaccess the current COMMDS. When access to the current COMMDS is suspended, SMS is able to access the new COMMDS without accessing the current COMMDS and resulting in further errors.

Without a usable COMMDS, the systems in the SMS complex have no means of communication. Other systems in the SMS complex are aware of the error, but they are unaware of the switch to a new COMMDS until you inform them.

If you can access the current COMMDS but you want to use an alternate one, you only need to issue the SETSMS command from one system. The other systems in the SMS complex detect the change from the old COMMDS to the new COMMDS and they automatically switch to the new one.