Databases Reference
In-Depth Information
Table 14-4.
Status for Online Redo Log File Members in the V$LOGFILE View
Status
Meaning
INVALID
The log file member is inaccessible, or it has been recently created.
DELETED
The log file member is no longer in use.
STALE
The log file member's contents are not complete.
NULL
The log file member is being used by the database.
It's important to differentiate between the STATUS column in V$LOG and the STATUS column in V$LOGFILE.
The STATUS column in V$LOG reflects the status of the log group. The STATUS column in V$LOGFILE reports the
status of the physical online redo log file member.
Restoring After Losing One Member of a Multiplexed Group
Problem
You notice this message in your alert.log file:
ORA-00312: online log 2 thread 1: '/u02/oraredo/o12c/redo02b.rdo'
You are experiencing media failure with one member of a multiplexed online redo log group and need to restore
the damaged online redo log file member.
Solution
If your online redo log file members are multiplexed, the log writer will continue to function as long as it can
successfully write to one member of the current log group. If the problem is temporary, then as soon as the online redo
log file becomes available, the log writer will start to write to the online redo log file as if there were never an issue.
If the media failure is permanent (such as a bad disk), then you'll need to replace the disk and drop and re-create
the bad member to its original location. If you don't have the option of replacing the bad disk, then you'll need to drop
the bad member and re-create it in an alternate location.
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.
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:
