rdbms' = '11.1.0.0.0';
Diskgroup altered.
SQL>
112 Oracle Database 11g DBA Handbook
The only side effect to using a higher compatibility level for the RDBMS and ASM instance is
that only other instances with a version number 11.1.0.0.0 or higher can access this disk group.
Next, set the disk group attribute disk_repair_time as in this example:
SQL> alter diskgroup data set attribute
2 'disk_repair_time' = '2.5h';
Diskgroup altered.
SQL>
The default disk repair time is 3.6 hours, which should be more than adequate for most
planned and unplanned (transient) outages. Once the disk is back online, run this command
to notify the ASM instance that the disk DATA_0001 is back online:
SQL> alter diskgroup data online disk data_0001;
Diskgroup altered.
SQL>
This command starts the background procedure to copy all changed extents on the remaining
disks in the disk group to the disk DATA_0001 that is now back online.
Altering Disk Groups
Disks can be added and dropped from a disk group; also, most characteristics of a disk group can
be altered without re-creating the disk group or impacting user transactions on objects in the disk
group.
When a disk is added to a disk group, a rebalance operation is performed in the background
after the new disk is formatted for use in the disk group. As mentioned earlier in this chapter, the
speed of the rebalance is controlled by the initialization parameter ASM_POWER_LIMIT.
Continuing with our example in the preceding section, suppose you decide to improve the
I/O characteristics of the disk group DATA by adding the last available raw disk to the disk group,
as follows:
SQL> alter diskgroup data
2 add failgroup d1fg3 disk '/dev/raw/raw8' name d1c;
Diskgroup altered.
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