Where to obtain diagnostic information
If Db2® is unable to access the keystore, or if it encounters a problem during its interaction with the keystore, it places diagnostic information into the Db2 diagnostic log (db2diag.log).
In addition, if you are using a centralized keystore, the keystore might record diagnostic information of its own that could further clarify the problem. Centralized keystores often use a diagnostic logging facility to record such information.