124.You are managing Oracle Database 11g with an ASM storage with high redundancy. The following
command was issued to drop the disks from the dga disk group after five hours:
ALTER DISKGROUP dga OFFLINE DISKS IN FAILGROUP f2 DROP AFTER 5H;
Which statement is true in this scenario?
A. It starts the ASM fast mirror resync.
B. All the disks in the dga disk group would be OFFLINE and the DISK_REPAIR_TIME disk attribute
would be set to 5 hours.
C. It drops all disk paths from the dga disk group.
D. All the disks in the dga disk group in failure group f2 would be OFFLINE and the DISK_REPAIR_TIME
disk attribute would be set to 5 hours.
Answer: D
答案解析：
参考：http://docs.oracle.com/cd/E11882_01/server.112/e41084/statements_1007.htm#BABEJJID
Use the disk_offline_clause to take one or more disks offline. This clause fails if the redundancy level of the disk group would be violated by
taking the specified disks offline.
Specify disk_name as shown in the NAME column of the V$ASM_DISK dynamic performance view.
The QUORUM and REGULAR keywords have the same semantics here as they have when adding a disk to a disk group.
By default, Oracle ASM drops a disk shortly after it is taken offline. You can delay this operation by specifying the timeout_clause, which gives you the opportunity to repair the disk and bring it back online. You
can specify the timeout value in units of minute or hour. If you omit the unit, then the default is hour.
You can change the timeout period by specifying this clause multiple times. Each time you specify it, Oracle ASM measures the time from the most recent previous disk_offline_clause while the disk group is mounted.
To learn how much time remains before Oracle ASM will drop an offline disk, query therepair_timer column of V$ASM_DISK.
This clause overrides any previous setting of the disk_repair_time attribute.