Oracle Oracle Certifications 1Z0-053 Questions & Answers

• Question 661:

  Which background process coordinates the rebalance activity for disk groups?

  A. ORBn

  B. OSMB

  C. RBAL

  D. ASMn

  Correct Answer: C

  RBAL ASM Rebalance Master Process Coordinates rebalance activity In an ASM instance, it coordinates rebalance activity for disk groups. In a database instances, it manages ASM disk groups.

• Question 662:

  To reference existing ASM files, you need to use a fully qualified ASM filename. Your development database has a disk group named DG2A, the database name is DEV19, and the ASM file that you want to reference is a datafile for the USERS02 tablespace.

  Which of the following is a valid ASM filename for this ASM file?

  A. dev19/+DG2A/datafile/users02.701.2

  B. +DG2A/dev19/datafile/users02.701.2

  C. +DG2A/dev19/users02/datafile.701.2

  D. +DG2A.701.2

  E. +DG2A/datafile/dev19.users.02.701.2

  Correct Answer: B

  Fully Qualified File Name Form (link)

  A fully qualified file name has the following form:

  +diskgroup/dbname/filetype/filetypetag.file.incarnation

  Where:

  +diskgroup is the disk group name preceded by a plus sign. You can think of the plus sign (+) as the root directory of the Oracle ASM file system, similar to the slash (/) on UNIX or Linux computers.

  dbname is the DB_UNIQUE_NAME of the database to which the file belongs. filetype is the Oracle file type and can be one of the file types shown in Table 7-3. filetypetag is type-specific information about the file and can be one of the tags

  shown in Table 7-3.

  file.incarnation is the file/incarnation pair, used to ensure uniqueness.

  For example,

  filetype = 'DATAFILE', Data files and data file copies filetypetag = 'tblspname', Name of the tablespace into which the file is added

• Question 663:

  How can you reverse the effects of an ALTER DISKGROUP ... DROP DISK command if it has NOT yet 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.

  Correct Answer: B

• Question 664:

  As DBA for the Rebalance, you have decided that you need to facilitate some redundancy in your database. Using ASM, you want to create a disk group that will provide for the greatest amount of redundancy for your ASM data (you do not have advanced SAN mirroring technology available to you, unfortunately).

  Which of the following commands would create a disk group that would offer the maximum in data redundancy?

  

  A. B. C. D. E.

  Correct Answer: C

  No SAN mirroring available means no external redundancy available. The highest redundancy of ASM is the HIGH redundancy with 3 mirror copies.

• Question 665:

  When starting up your ASM instance, you receive the following error: SQL> startup pfile=$ORACLE_HOME/dbs/init+ASM.ora ASM instance started

  Total System Global Area 104611840 bytes Fixed Size 1298220 bytes Variable Size 78147796 bytes ASM Cache 25165824 bytes

  ORA-15032: not all alternations performed ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DGROUP3" ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DGROUP2" ORA-15063: ASM discovered an insufficient number of disks for diskgroup "DGROUP1"

  In trying to determine the cause of the problem, you issue this query: SQL> show parameter asm

  

  What is the cause of the error?

  A. The ASM_DISKGROUPS parameter is configured for three disk groups: DGROUP1, DGROUP2, and DGROUP3. The underlying disks for these disk groups have apparently been lost.

  B. The format of the ASM_DISKGROUPS parameter is incorrect. It should reference the disk group numbers, not the names of the disk groups

  C. The ASM_POWER_LIMIT parameter is incorrectly set to 1. It should be set to the number of disk groups being attached to the ASM instance.

  D. The ASM_DISKSTRING parameter is not set; therefore disk discovery is not possible.

  E. There is insufficient information to solve this problem.

  Correct Answer: D

  ASM_DISKSTRING specifies an operating system-dependent value used by Automatic Storage Management to limit the set of disks considered for discovery. When a new disk is added to a disk group, each Automatic Storage Management instance that has the disk group mounted must be able to discover the new disk using the value of ASM_DISKSTRING. In most cases, the default value will be sufficient.

  Using a more restrictive value may reduce the time required for Automatic Storage Management to perform discovery, and thus improve disk group mount time or the time for adding a disk to a disk group. A "?" at the beginning of the string gets expanded to the Oracle home directory. Depending on the operating system, wildcard characters can be used. It may be necessary to dynamically change ASM_DISKSTRING before adding a disk so that the new disk will be discovered. An attempt to dynamically modify ASM_DISKSTRING will be rejected and the old value retained if the new value cannot be used to discover a disk that is in a disk group that is already mounted.

  Refer to here

• Question 666:

  When an ASM instance receives a SHUTDOWN NORMAL command, what command does it pass on to all database instances that rely on the ASM instances disk groups?

  A. TRANSACTIONAL

  B. IMMEDIATE

  C. ABORT

  D. NORMAL

  Correct Answer: C

• Question 667:

  Which initialization parameter in an ASM instance specifies the disk groups to be automatically mounted at instance startup?

  A. ASM_DISKMOUNT

  B. ASM_DISKGROUP

  C. ASM_DISKSTRING

  D. ASM_MOUNTGROUP

  Correct Answer: B

  Refer to here When you run the STARTUP command, this command attempts to mount the disk groups specified by the initialization parameter ASM_DISKGROUPS. If you have not entered a value for ASM_DISKGROUPS, then the ASM instance starts and Oracle displays an error that no disk groups were mounted. You can then mount disk groups with the ALTER DISKGROUP...MOUNT command.

• Question 668:

  What is the default AU size of an ASM disk group? What is the maximum AU size in an ASM disk group?

  A. 100KB default, 10TB maximum

  B. 256KB default, 1024MB maximum

  C. 10MB default, 126PB maximum

  D. 64KB default, 1EB maximum

  E. 1MB default, 64MB maximum

  Correct Answer: E

  The AU size is determined at creation time with the allocation unit size (AU_SIZE) disk group attribute. The values can be 1, 2, 4, 8, 16, 32, and 64 MB.

  Refer to here

• Question 669:

  What is the result of increasing the value of the parameter ASM_POWER_LIMIT during a rebalance operation?

  A. The ASM rebalance operation will likely consume fewer resources and complete in a shorter amount of time.

  B. The ASM rebalance operation will consume fewer resources and complete in a longer amount of time.

  C. The ASM rebalance operation will be parallelized and should complete in a shorter amount of time.

  D. There is no ASM_POWER_LIMIT setting used in ASM.

  E. None of the above

  Correct Answer: C

• Question 670:

  Which of the following is a benefit of ASM fast disk resync?

  A. Failed disks are taken offline immediately but are not dropped.

  B. Disk data is never lost.

  C. By default, the failed disk is not dropped from the disk group ever, protecting you from loss of that disk.

  D. The failed disk is automatically reformatted and then resynchronized to speed up the recovery process.

  E. Hot spare disks are automatically configured and added to the disk group.

  Correct Answer: A

  ASM Fast Mirror Resync