ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM], [Check traces and OS configuration], [Check Oracle document and MOS notes]

When working with Oracle DB Version 19.5 recently noticed below errors in alert.log file

Starting background process VKTM
2020-02-04T17:05:58.711181-08:00
Errors in file /home/oracle/diag/rdbms/testdb/TESTDB/trace/TESTDB_vktm_43832.trc (incident=42521):
ORA-00800: soft external error, arguments: [Set Priority Failed], [VKTM], [Check traces and OS configuration], [Check Oracle document and MOS notes], []
Incident details in: /home/oracle/diag/rdbms/testdb/TESTDB/incident/incdir_42521/TESTDB_vktm_43832_i42521.trc
2020-02-04T17:05:58.713567-08:00
Error attempting to elevate VKTM's priority: no further priority changes will be attempted for this process
VKTM started with pid=5, OS id=43832

After research found that parameter _high_priority_processes="VKTM" may help, but it is a internally parameter you cannot able to apply directly on SPFILE. I always raise a ticket with Oracle support to got the confirmation before making changes.

This issue has been reported in the internal bug - Bug 30664554 : ORA-00800: SOFT EXTERNAL ERROR, ARGUMENTS: [SET PRIORITY FAILED], [VKTM]
In order to update internal parameters on a DB using SPFILE you need to follow bellows steps.

1. Take a backup of SPFILE and PFILE to revert changes in case of any isuses.
2. Create PFILE from SPFILE
SQL> create pfile=’$ORACLE_HOME/dbs/initTESTDB.ora’ from spfile
3. Add/update the parameter in PFILE
4. Rename SPFILE and stop/start the DB to use PFILE that was created
5. Create SPFILE from PFILE
SQL> create SPFILE=’$ORACLE_HOME/dbs/spfileTESTDB.ora’ from pfile;
6. stop/start the DB to use SPFILE that was created
Now the changes are applied to SPFILE.

Note that every environment, errors, load, use cases are different, I would highly recommend users to open a ticket with Oracle support and get confirmation before making any changes to your databases.
Thanks
Satishbabu Gunukula,ORACLE ACE
https://oracleracexpert.com