Immediately after adding a new disk to or removing an existing disk from an ASM instance, you find that the
performance of the database goes down initially until the time the addition or removal process is completed,
and then gradually becomes normal.
Which two activities would you perform to maintain a consistent performance of the database while adding or
removing disks? (Choose two.)
A.
Define the POWER option while adding or removing the disks.
B.
Increase the number of ARB processes by setting up a higher value for ASM_POWER_LIMIT.
C.
Increase the number of DBWR processes by setting up a higher value for DB_WRITER_PROCESSES.
D.
Increase the number of slave database writer processes by setting up a higher value for
DBWR_IO_SLAVES.
Explanation:
ARBn (ASM Rebalance Process): Rebalances data extents within an ASM disk group, possible processes are
ARB0-ARB9 and ARBA.
ALTER DISKGROUP..POWER clause, specify a value from 0 to 11, where 0 stops the rebalance operation and
11 permits Oracle ASM to execute the rebalance as fast as possible. The value you specify in the POWER
clause defaults to the value of the ASM_POWER_LIMIT initialization parameter. If you omit the POWER
clause, then Oracle ASM executes both automatic and specified rebalance operations at the power determined
by the value of the ASM_POWER_LIMIT initialization parameter.
Note:
Beginning with Oracle Database 11g Release 2 (11.2.0.2), if the COMPATIBLE.ASM disk group attribute is set
to 11.2.0.2 or higher, then you can specify a value from 0 to 1024 in the POWER clause.