You suspect that the disk itself is okay. You know it will take 24 hours to replace the controller and you

don't want to have to rebuild the disks from scratch. What do you do?

A. Take the whole disk group offline and wait for the controller card to be installed. Once it's installed,

bring the disk group online again.

B. Change the ASM parameter ASM_PREFERRED_READ_FAILURE_GROUPS to indicate that you

want to read from the non-failed disk. Once the disk controller is replaced, reset the parameter to its

original value.

C. You have no choice but to rebuild the disk. Drop the disk from the disk group and wait for the controller

to be replaced. Once the controller is replaced, add the disk back into the disk group and allow ASM to

rebuild it.

D. If you are using any setting other than REDUNDANCY EXTERNAL for your disk group, you will have to

recover any data on that disk from a backup. The database will be unavailable until you can correct the

problem and perform recovery.

E. Change the attribute DISK_REPAIR_TIME on the disk group to a time greater than 24 hours.

Answer: E

官方文档：http://docs.oracle.com/cd/E11882_01/server.112/e10803/config_storage.htm#HABPT4813

The DISK_REPAIR_TIME disk group attribute specifies how long a disk remains offline before Oracle ASM drops the disk. If a disk is made available before the DISK_REPAIR_TIME parameter has expired, the storage administrator can issue the ONLINE DISK command and Oracle ASM resynchronizes the stale data from the mirror side. In Oracle Database 11g, the online disk operation does not restart if there is a failure of the instance on which the disk is running. You must reissue the command manually to bring the disk online.

You can set a disk repair time attribute on your disk group to specify how long disks remain offline before being dropped. The appropriate setting for your environment depends on how long you expect a typical transient type of failure to persist.

Set the DISK_REPAIR_TIME disk group attribute to the maximum amount of time before a disk is definitely considered to be out of service.