What do you do?

You are an Oracle DBA responsible for an ASM instance. The disk controller on your system fails.
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?

You are an Oracle DBA responsible for an ASM instance. The disk controller on your system fails.
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.



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Helcio

Helcio

I think that B is correct because we can use a Failure group that was created on another disk controller.

What are Diskgroup’s and Failuregroups?

Diskgroup is a terminology used for logical structure which holds the database files. Each Diskgroup consists of Disks/Raw devices where the files are actually stored. Any ASM file is completely contained within a single disk group. However, a disk group might contain files belonging to several databases and a single database can use files from multiple disk groups.

Failuregroups are used when using Normal/High Redundancy. They contain the mirrored ASM extents and must be containing different disks and preferably on separate disk controller.