Exadata cell optimized incremental backup can skip backing up blocks

Asset ID:	1-77-1615180.1
Update Date:	2014-02-07
Keywords:

Solution Type Sun Alert Sure

Solution 1615180.1 : Exadata cell optimized incremental backup can skip backing up blocks

Applies to:

Exadata Database Machine X2-2 Hardware - Version All Versions and later
Exadata Database Machine X2-8 - Version All Versions and later
Exadata X3-2 Hardware - Version All Versions and later
Exadata X3-8 Hardware - Version All Versions and later
Exadata X4-2 Hardware - Version All Versions and later
Information in this document applies to any platform.

Description

Exadata cell optimized incremental backup can miss some blocks if a database file grows larger while the file is being backed up. A missed block can lead to stuck recovery and ORA-600[3020] errors if the incremental backup is used for media recovery.

(See: Exadata Critical Issue Note: 1270094.1 - Issue DB23)

Occurrence

This applies to RMAN incremental backups created with one of the following database patch sets:

12.1.0.1 GIPSU1 or earlier
11.2.0.3 BP21 or earlier
any 11.2.0.2
any 11.2.0.1

Existing RMAN incremental backups taken without the bug fix in place should be considered invalid and not usable for database recovery, incrementally updating level 0 backups, or standby database creation.

RMAN full backups, level 0 backups that are not part of an incrementally updated backup strategy, and database recovery using archived redo logs are not affected by this issue.

Symptoms

User will hit an ORA-600[3020] during media recovery after applying incremental backup taken in an Exadata environment.

See Document 16057129.8 for details.

Workaround

Workaround Steps:

Set the following parameter in all databases that use Exadata storage:

_disable_cell_optimized_backups=TRUE

SQL> alter system set "_disable_cell_optimized_backups"=TRUE scope=both;

The parameter specified above may be removed after the fix for <bug 16057129> is installed by upgrade or by applying an interim patch. See patches section for patch availability.

2. Create new RMAN backups. At a minimum, a new RMAN cumulative incremental backup must be taken. In addition, level 0 backups that are part of an incrementally updated backup strategy must be recreated.

Patches

Fixed in 12.1.0.1 GIPSU2
Fixed in Patch 16057129 for 12.1.0.1 GIPSU1
Fixed in 11.2.0.4.0
Fixed in 11.2.0.3 BP22
Fixed in Patch 16057129 for 11.2.0.3 BP21
Fixed in Patch 17599908 for 11.2.0.2 BP22

History

[17-JAN-2014] - creation

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