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Oraclelearner
Hello,

Can anyone tell me the required steps to be taken to mirror the redo log files. Right now, one of our production databases have three redo log groups (two members each) on the same disk.

I'm sure I know the steps required, but I just want to make sure before doing this.

Thanks in advance,
Oraclelearner
SteveC
Have members of a group live on different disks.
burleson
Hi,

Steve is right, the mirrors MUST be on a separate disk spindle.

Oracle redo log mirroring allows a redo log can be simultaneously copied to multiple disks at the same time by the LGWR process.

This ensures that the loss of a group of log files will not affect operation. Groups are archived together. The MAXLOGMEMBERS parameter in the CREATE DATABASE statement determines the maximum number of redo logs in a group. The MAXLOGFILES parameter in the CREATE DATABASE statement determines the maximum number of groups. The reason that the MAXLOGFILES parameter is MAXLOGFILES and not MAXLOGGROUPS is that it is a carryover from the days before you could have multiple log members, as well as multiple log groups.

See here for more details on redo log miroring:

http://www.dba-oracle.com/t_ault_27_lgwr_m...maxlogfiles.htm
Oraclelearner
Thanks Steve and Mr. Burleson for your replies
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