Database Reference
In-Depth Information
For permanent media failures, follow these instructions for dropping and re-creating one member of an online
redo log group:
1.
Identify the online redo log file experiencing media failure (inspect the
alert.log
).
2.
Ensure that the online redo log file is not part of the current online log group.
3.
Drop the damaged member.
4.
Add a new member to the group.
To begin, open your
alert.log
file and look for an
ORA-00312
message that identifies which member of the log
group is experiencing media failure. You should see lines similar to these in your
alert.log
file:
ORA-00312: online log 2 thread 1: '/u02/oraredo/O12C/redo02b.rdo'
Errors in file
/u01/app/oracle/diag/rdbms/o12C/O12C/trace/O12C_lgwr_10531.trc:
This message tells you which log member has failed. The
alert.log
file output also specifies that a trace file has
been generated. You'll find additional information about the bad member in the specified trace file:
ORA-00313: open failed for members of log group 2 of thread 1
ORA-00312: online log 2 thread 1: '/u02/oraredo/O12C/redo02b.rdo'
ORA-27037: unable to obtain file status
Linux-x86_64 Error: 2: No such file or directory
ORA-00321: log 2 of thread 1, cannot update log file header
ORA-00312: online log 2 thread 1: '/u02/oraredo/O12C/redo02b.rdo'
From the prior output, a member of the online redo log group 2 is having issues. Once you've identified the bad
online redo log file, execute the following query to check whether that online redo log file's group has a CURRENT
status (in this example, we're interested in group 2):
SELECT group#, status, archived, thread#, sequence#
FROM v$log;
Here is some sample output indicating that group 2 is not the current log:
GROUP# STATUS ARC THREAD# SEQUENCE#
---------- ---------------- --- ---------- ----------
1 CURRENT NO 1 25
3 INACTIVE NO 1 24
2 INACTIVE NO 1 23
■
if you attempt to drop a member of a current log group, Oracle will throw an ORA-01609 error specifying that
the log is current and you cannot drop one of its members.
Note
If the failed member is in the current log group, then use the
alter system switch logfile
command to make
the next group the current group. Then drop the failed member as follows:
SQL> alter database drop logfile member '/u02/oraredo/O12C/redo02b.rdo';
