21.
As the DBA, you run the following query on your ASM instance. What is the implication of
the results of the query? (Choose two.)
SQL> select group_number, name, state from v$ASM_DISKGROUP;
GROUP_NUMBER NAME STATE
------------ ------------------------------ -----------
0 DGROUP1 DISMOUNTED
2 DGROUP2 MOUNTED
3 DGROUP3 MOUNTED
GROUP_NUMBER NAME STATE
------------ ------------------------------ -----------
0 DGROUP1 DISMOUNTED
2 DGROUP2 MOUNTED
3 DGROUP3 MOUNTED
- A.The DGROUP1 disk group was unmounted by another DBA.
- B.A datafile has been lost, causing the ASM disk group DGROUP1 to go into the DISMOUNTED state.
- C.One of the redundant disks (DGROUP1) has been lost in a disk group.
- D.This query has no meaning in an ASM instance.
- E.A disk associated with a disk group was discovered after the ASM instance initially opened.
- Answer & Explanation
- Report
Answer : [A, E]
Explanation :
Explanation :
| Apparently, for some reason DGROUP1 was not mounted when the ASM instance was started, or the disk was missing and then reappeared (hardware failure perhaps) after the ASM instance was started. ASM will discover new disks, even after the ASM instance is opened. |
22.
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.
- Answer & Explanation
- Report
Answer : [E]
Explanation :
Explanation :
| The DISK_REPAIR_TIME attribute will prevent Oracle from automatically dropping the disk in the disk group for a specific period of time. This gives you time to replace the controller indicated in the question. |
23.
If you use ALTER DISKGROUP … ADD DISK and specify a wildcard for the discovery string,
what happens to disks that are already a part of the same or another disk group?
- A.The command fails unless you specify the FORCE option.
- B.The command fails unless you specify the REUSE option.
- C.The command must be reissued with a more specific discovery string.
- D.The other disks, already part of the disk group, are ignored.
- Answer & Explanation
- Report
Answer : [D]
Explanation :
Explanation :
| The ALTER DISKGROUP … ADD DISK command adds all disks that match the discovery string but are not already part of the same or another disk group. |
24.
Which of the following ALTER DISKGROUP commands does not use V$ASM_OPERATION to
record the status of the operation?
- A.ADD DIRECTORY
- B.DROP DISK
- C.RESIZE DISK
- D.REBALANCE
- E.ADD FAILGROUP
- Answer & Explanation
- Report
Answer : [A]
Explanation :
Explanation :
| The ADD DIRECTORY command is not likely to use V$ASM_OPERATION to track its progress, because this operation adds only a small amount of metadata—a directory object—to the disk group and takes a minimal amount of time to complete. The V$ASM_OPERATION view provides the status of long-running ASM operations. |
25.
How can you reverse the effects of an ALTER DISKGROUP … DROP DISK command if it has
already completed?
- A.Issue the ALTER DISKGROUP … ADD DISK command.
- B.Issue the ALTER DISKGROUP … UNDROP DISKS command.
- C.Issue the ALTER DISKGROUP … DROP DISK CANCEL command.
- D.Retrieve the disk from the Recycle Bin after the operation completes.
- Answer & Explanation
- Report
Answer : [A]
Explanation :
Explanation :
| If the DROP DISK operation has already completed, you must use ALTER DISKGROUP … ADD DISK to add the disk back to the disk group. In any case, the disk group is continuously available to all users and no data is lost. |
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