Use
If the
volumes of your
database instance are mirrored, one of the volume mirrors may fail. In this case, the database continues to operate but only the part of the volume pair that is intact can be accessed. The faulty volume mirror is displayed as a Bad volume.
You use this function to recover a damaged mirror
log volume. 
To ensure the downtime security of your system, it is advisable to mirror log volumes.
We recommend RAID 5 configurations to protect your data volumes.
Recovering a damaged log volume mirror
If you trigger the recovery of a log volume, it is only reinitialized. In other words, the data is not copied from the intact volume to the recovered volume. The system then writes to both log volumes sequentially. The volume originally marked
BAD must be filled once before the contents of both volumes are identical again and both volumes can be read.The defective volume remains marked
BAD during the entire reintegration phase.Prerequisites
The database instance is the
ONLINE or the ADMIN operational state.Procedure