Oracledb12c中，每次日志切換時，會改變alert_sid.log的權限

Oracledb12c中，每次日志切換時，會改變alert_sid.log的權限

12c中，每次日志切換時，會改變alert_sid.log的權限

適用於：
Oracle Database - Enterprise Edition - Version 12.1.0.1 and later
Information in this document applies to any platform.

症狀：

When trying to set the group write bit in the OS Permissions for the alert log file it gets reset after every log switch

For example:
[oracle@rhel59 trace]$ pwd
/u01/app/oracle/diag/rdbms/orcl/orcl/trace
[oracle@rhel59 trace]$ ls -lrt alert_orcl.log 
-rw-r----- 1 oracle oinstall 357531 May  2 07:30 alert_orcl.log --->此時的權限為640
[oracle@rhel59 trace]$ 

--修改為666
[oracle@rhel59 trace]$ chmod 666 alert_orcl.log
[oracle@rhel59 trace]$ ls -lrt alert_orcl.log 
-rw-rw-rw- 1 oracle oinstall 357988 May  2 07:42 alert_orcl.log--->此時的權限為666


--日志切換
SQL> alter system switch logfile;

System altered.


--再次查看權限
[oracle@rhel59 trace]$ ls -lrt alert_orcl.log 
-rw-r--rw- 1 oracle oinstall 358240 May  2 07:50 alert_orcl.log--->此時的權限為646
[oracle@rhel59 trace]$

原因：

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.

解決方案：

chmod 770 //diag/rdbms//

 Then restart the database