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Loss/Corruption of one member of multiplexed Redo Log group

T.BoydDec 16 2015 — edited Dec 16 2015

Grid Infrastructure: 11.2.0.4

DB version: 11.2.0.4

OS : RHEL 6.5

All redo logs are Multiplexed once ie. One mirror copy

I am creating a document on how to deal with Loss of one member of a multiplexed Redo Log group. It applies to DBs in ASM or Linux Filesystem.

If one member of a multiplexed Redo log group is lost/corrupted which is in CURRENT or ACTIVE state (v$log.status) , will the following work ?

Assuming the DB wouldn't crash (well that is the whole point of multiplexing )

Step1. Switch the redo log group and bring it to INACTIVE state ie. LGWR is not writing to it now


Step2. Drop the Lost/corrupt member .

  ALTER DATABASE DROP LOGFILE MEMBER '+DATA_DG1/mbhsprd/onlinelog/group_1.256.834497203';

Apparently, this command does not actually delete the log file at ASM/OS Level; it only updates the control file

Step3. If it is a corrupted logfile then Physically remove the corrupted file from ASM/OS location

Step4. Hopefully the below will create a mirror copy of the surviving member

ALTER DATABASE ADD LOGFILE MEMBER '+DATA_DG1/mbhsprd/onlinelog/group_1.256.834497203' TO GROUP 3;

Will the above steps work ?

This post has been answered by JohnWatson2 on Dec 16 2015
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