Where possible, use VSAM REWRITE only on records retrieved by a READ KEY without UPDATE first. Or use EXEC SQL if the data is in Db2 in z/OS – it provides more granular locking and missing-key handling.
When accessing a VSAM file via an alternate index path, the underlying primary key is used for exclusive locking. If the AIX key translates to a primary key that has been deleted, but the AIX index hasn’t been updated, the error occurs. mvsckey not found exclusive
Depending on the cause, here’s how to resolve it: Where possible, use VSAM REWRITE only on records
| Cause | Action |
|-------|--------|
| GRS Contention | Cancel the job or subsystem holding the exclusive ENQ. Use F GRS,RESET only as a last resort. |
| Deadlock | IMS: Issue /DISPLAY TRANSACTION to find hung units of work. CICS: Use CEMT I TASK to identify and force-purge the offending task. |
| Corrupt lock table | Restart GRS (requires IPL in most cases) or restart the failing subsystem (e.g., IMS control region). |
| Monitoring tool bug | Apply the latest PTF for the monitoring product or temporarily disable its storage key hooks via a PARMLIB override. | When accessing a VSAM file via an alternate
The service account running ESET services (e.g., NT AUTHORITY\SYSTEM) may lack exclusive write access to the database file because another process (or a manual lock) is holding it open.
Performance monitors (e.g., Omegamon, MainView) sometimes hook into STORAGE KEY management. A bug in these tools can incorrectly report that an exclusive lock is missing when attempting to modify key-protected storage.
