Recovering an ACDS

You can recover from errors that prevent access to the ACDS if you have allocated a spare. All permanent errors that make the ACDS unreadable or unwritable require intervention. For permanent I/O errors to the ACDS, the messages IGD041I and IGD040D appear on the operator console. You have the option of retrying the failing operation or using the spare ACDS.

If you decide to use the spare ACDS, you need to perform three steps.

Reply 'C' on the operator console.
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Copy the data from the SMS address space to the spare ACDS by issuing the following command from a system in the SMS complex:
```
SETSMS SAVEACDS(spare.acds)
```
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Tell the system to use the spare ACDS by issuing the following command:
```
SETSMS ACDS(spare.acds)
```

You need only to issue the SETSMS ACDS(spare.acds) command on one system. The COMMDS is updated to reflect this change. As the other systems in the SMS complex access the COMMDS (based on the INTERVAL value in their respective IGDSMSxx members), they automatically switch to the new ACDS.

Note: In addition to the method previously described, you can also use the SETSMS COPYSCDS command to create an ACDS from any valid SCDS. This command may be especially useful in cases where the created ACDS is to be used on another system, such as in disaster recovery situations. See z/OS MVS System Commandsfor more information on the SETSMS COPYSCDS command.

If your ACDS is corrupted, you should recover it from a good backup copy of the SCDS. Do not use the SETSMS SAVEACDS command after the error that corrupted the ACDS. To replace the ACDS:

Define a new linear VSAM data set with SHROPTNS(3,3), REUSE and more space for the new ACDS.
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Issue the command SETSMS ACDS(newacdsdsn),SCDS(scdsdsn) to switch the sysplex over to the new ACDS.
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Ensure PARMLIB member IGDSMSxx is updated to reflect the new ACDS so that it will be used upon the IPL of any system in the sysplex.
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Note: If replacing the corrupted ACDS with a new ACDS does not solve the problem, try reallocating and activating both a new ACDS and a new COMMDS, using the procedure described above.