3018 abend in DCMT VARY AREA OFFLINE/RETRIEVAL
Article ID: 29156
Updated On:
Products
Issue/Introduction
When trying to issue DCMT VARY AREA OFFLINE or RETRIEVAL, the command abends with a 3018 abend code.
Environment
Release: All supported releases.
Cause
This means that something outside of the IDMS CV has turned off the IN USE FOR UPDATE flag in the first page of the area that was set when the area was put into UPDATE mode by the CV (at startup if the area is defined to be set to UPDATE at startup, or when varied from OFFLINE or RETRIEVAL to UPDATE).
When the CV sets an area status to UPDATE, it reads the first page of the area and sets an IN USE FOR UPDATE flag in the page footer and writes it back to the dataset. This prevents any other job from readying the area in update mode.
Resolution
When performing maintenance against an area, it must be varied OFFLINE or RETRIEVAL in the CV.
If a batch local UNLOCK utility is run while the CV has that area in UPDATE mode, then the IN USE FOR UPDATE flag is turned off, but if the area had not been varied to OFFLINE or RETRIEVAL, the CV still considers the area locked for update. The area is now vulnerable to be corrupted since no IN USE FOR UPDATE lock is set and the CV as well as other jobs or CVs would be able to update simultaneously.
Another way this could happen would be if the area was FORMATted, or restored from a backup while the CV has it locked for update. Either of these is much more serious and could result in a corrupted database that requires manual recovery.
Such a 3018 error means it is recommended to shutdown the CV ASAP and investigate what caused the IN USE FOR UPDATE flag to be turned off and recover accordingly.
Note: The command DCMT VARY FILE xxx ACTIVE against the first file in the area will reset the locking bit without altering the area's status within the CV, but the original reason for the problem must still be determined.
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