nerdexam
Oracle

1Z0-062 · Question #203

A database uses Automatic storage Management (ASM) as database storage, which has diskgroup, DATA1, which is created as follows: What happens when the FAILGRP1 failure group is corrupted?

The correct answer is C. ASM does not mirror any data and newly allocated primary allocation units (AU) are stored in the. When an ASM diskgroup is created with EXTERNAL REDUNDANCY, ASM performs no mirroring, so corruption of one failure group means no automatic failover - new primary allocation units are directed to the surviving failure group.

Managing Database Storage Structures

Question

A database uses Automatic storage Management (ASM) as database storage, which has diskgroup, DATA1, which is created as follows:

What happens when the FAILGRP1 failure group is corrupted?

Options

  • AMirroring of allocation units occurs within the FAILGRP2 failure.
  • BTransactions that are using diskgroup fail.
  • CASM does not mirror any data and newly allocated primary allocation units (AU) are stored in the
  • DData in the FAILGRP1 failure group is move to the FAILGRP2 failure group and rebalancing is

How the community answered

(65 responses)
  • A
    5% (3)
  • B
    2% (1)
  • C
    85% (55)
  • D
    9% (6)

Why each option

When an ASM diskgroup is created with EXTERNAL REDUNDANCY, ASM performs no mirroring, so corruption of one failure group means no automatic failover - new primary allocation units are directed to the surviving failure group.

AMirroring of allocation units occurs within the FAILGRP2 failure.

Internal mirroring of allocation units within FAILGRP2 only occurs with NORMAL REDUNDANCY (2-way mirror) or HIGH REDUNDANCY (3-way mirror) diskgroups; with EXTERNAL REDUNDANCY, ASM performs no mirroring at all.

BTransactions that are using diskgroup fail.

Transactions using the diskgroup do not universally fail upon FAILGRP1 corruption under EXTERNAL REDUNDANCY - only data stored on the corrupted disks in FAILGRP1 is inaccessible, and the scope of impact depends on which extents resided there.

CASM does not mirror any data and newly allocated primary allocation units (AU) are stored in theCorrect

With EXTERNAL REDUNDANCY specified in CREATE DISKGROUP, ASM delegates all redundancy to the underlying storage hardware and performs zero mirroring itself. When FAILGRP1 becomes corrupted, there are no ASM-managed mirror copies to serve as a failover, and new primary allocation units will be allocated from FAILGRP2 going forward - data previously stored exclusively in FAILGRP1 is not recoverable through ASM mechanisms.

DData in the FAILGRP1 failure group is move to the FAILGRP2 failure group and rebalancing is

ASM does not automatically migrate data away from a corrupted failure group in EXTERNAL REDUNDANCY mode; rebalancing in ASM is a disk-add or disk-drop operation, not a response to failure group corruption.

Concept tested: ASM diskgroup external redundancy and failure group corruption behavior

Source: https://docs.oracle.com/en/database/oracle/oracle-database/19/ostmg/asm-diskgroups.html

Topics

#ASM#disk group#failure group#data redundancy

Community Discussion

No community discussion yet for this question.

Sign up to join the discussion
Full 1Z0-062 Practice