[Translated from mos] in Oracle db 12c, The alert_sid.log permission is changed every time the log is switched. 12calert_sid.log
In 12c, The alert_sid.log permission is changed each time the log is switched.
Source:
Alert log file's permissions Change with every log switch in 12c (Doc ID 1637367.1)
Applicable:
Oracle Database-Enterprise Edition-Version 12.1.0.1 and later
Information in this document applies to any platform.
Symptoms:
When trying to set the group write bit in the OS Permissions for the alert log file it gets reset after every log switchFor example: [oracle @ rhel59 trace] $ pwd/u01/app/oracle/diag/rdbms/orcl/trace [oracle @ rhel59 trace] $ ls-lrt alert_orcl.log-rw-r ----- 1 oracle oinstall 357531 May 2 alert_orcl.log ---> the permission is 640 [oracle @ rhel59 trace] $ -- changed to 666 [oracle @ rhel59 trace] $ chmod 666 alert_orcl.log [oracle @ rhel59 trace] $ ls-lrt alert_orcl.log-rw-1 oracle oinstall 357988 May 2 alert_orcl.log ---> the permission is 666 -- log switch SQL> alter system switch logfile; system altered. -- view the permission again [oracle @ rhel59 trace] $ ls-lrt alert_orcl.log-rw-r -- rw-1 oracle oinstall 358240 May 2 07:50 alert_orcl.log ---> the permission is 646 [oracle @ rhel59 trace] $
Cause:
This is an expected behavior, if it is required to have the group write bit set for the alert log, then group write bit needs to be set for in the ADR home directory.
Solution:
chmod 770 /<SID>/diag/rdbms/<SID>/<SID> Then restart the database