ADVISE FAILURE

Purpose

Use the ADVISE FAILURE command to display repair options for the specified failures. This command prints a summary of the failures identified by the Data Recovery Advisor and implicitly closes all open failures that are already fixed.

The recommended workflow is to run the following commands in an RMAN session: LIST FAILURE to display failures, ADVISE FAILURE to display repair options, and REPAIR FAILURE to fix the failures.

Prerequisites

RMAN must be connected to a target database, which must be started. The target database must be a single-instance database and must not be a physical standby database, although it can be a logical standby database.

In the current release, Data Recovery Advisor only supports single-instance databases. Oracle Real Application Clusters (Oracle RAC) databases are not supported.

Usage Notes

Data Recovery Advisor verifies repair feasibility before proposing a repair strategy. For example, Data Recovery Advisor checks that all backups and archived redo log files needed for media recovery are available. The ADVISE FAILURE output indicates the repair strategy that Data Recovery Advisor considers optimal for a given set of failures. The ADVISE FAILURE command can generate both manual and automated repair options.

Manual Repair Options

Manual repair options are either mandatory or optional. The optional actions may fix the failures more quickly or easily than automated repairs. In other cases, the only options are manual because automated repairs are not feasible. For example, I/O failures often cannot be repaired automatically. Also, it is sometimes impossible to diagnose a failure because insufficient data is returned by the operating system or the disk subsystem.

Automated Repair Options

Each automated repair option is either a single repair or a set of repair steps (see Table 2-1, "Automated Repair Options" for a description of command output). When a repair option has a script that contains multiple repair steps, ADVISE FAILURE generates the script so that the repair steps are in the correct order. A single repair always fixes critical failures together. You must repair critical failures, but you can also repair noncritical failures at the same time. You can repair noncritical failures in a random order, one by one, or in groups.

Oracle RAC and Data Recovery Advisor

If a data failure brings down all instances of an Oracle RAC database, then you can mount the database in single-instance mode and use Data Recovery Advisor to detect and repair control file, SYSTEM datafile, and dictionary failures. You can also initiate health checks to test other database components for data failures. This approach will not detect data failures that are local to other cluster instances, for example, an inaccessible datafile.

Syntax

advise::=

Description of the illustration advise.gif

Semantics

advise

Syntax Element	Description
`ADVISE FAILURE`	Displays information for all `CRITICAL` and `HIGH` priority failures recorded in the automatic diagnostic repository. You can only use `ADVISE FAILURE` with no options when a `LIST FAILURE` command was previously executed in the current session. Note: If a new failure has been recorded in then diagnostic repository since the last `LIST` `FAILURE` command in the current RMAN session, then RMAN issues a warning before advising on `CRITICAL` and `HIGH` failures.
`ALL`	Lists options that repair all open failures together.
`CRITICAL`	Lists options that repair only critical failures.
`HIGH`	Lists options that repair only failures with `HIGH` priority.
`LOW`	Lists options that repair only failures with `LOW` priority.
`failureNumber`	Lists options that repair only the specified failures.
`EXCLUDE FAILURE` `failureNumber`	Excludes the specified failures from the list.

ADVISE FAILURE Command Output

The ADVISE FAILURE output includes the LIST FAILURE output, which is described in Table 2-26, "List of Failures". See Example 2-5 for sample output.

RMAN presents mandatory and optional manual actions in an unordered list. If manual options exist, then they appear before automated options. Table 2-1 describes the output for automated repair options.

Table 2-1 Automated Repair Options

Column	Indicates
`Option`	The identifier for the automated repair option.
`Strategy`	A strategy to fix the failure with the `REPAIR FAILURE` command. The Data Recovery Advisor always presents an automated repair option with no data loss when possible. Automated repair options fall into the following basic categories: Repair with no data loss Repair with data loss, for example, Flashback Database Note: The `ADVISE` command maps a set of failures to a the set of repair steps that Data Recovery Advisor considers to be optimal. When possible, Data Recovery Advisor consolidates multiple repair steps into a single repair. For example, if the database has corrupted datafile, missing control file, and lost current redo log group, then Data Recovery Advisor would recommend a single, consolidated repair plan to restore the database and perform point-in-time recovery.
`Repair Description`	A description of the proposed repair. For example, the proposed repair could be to restore and recover datafile 17.
`Repair Script`	The location of an editable script with all repair actions and comments. If you do not choose an automated repair, then you can review this script and edit it for use in a manual recovery strategy.

Examples

Example 2-5 Displaying Repair Options for All Failures

This example shows repair options for all failures known to the Recovery Data Advisor. The example indicates two failures: missing datafiles and a datafile with corrupt blocks.

RMAN> LIST FAILURE;
 
List of Database Failures
=========================
 
Failure ID Priority Status    Time Detected Summary
---------- -------- --------- ------------- -------
142        HIGH     OPEN      23-APR-07     One or more non-system datafiles are missing
101        HIGH     OPEN      23-APR-07     Datafile 1: '/disk1/oradata/prod/system01.dbf' 
                                            contains one or more corrupt blocks
 
RMAN> ADVISE FAILURE;
 
List of Database Failures
=========================
 
Failure ID Priority Status    Time Detected Summary
---------- -------- --------- ------------- -------
142        HIGH     OPEN      23-APR-07     One or more non-system datafiles 
                                            are missing
101        HIGH     OPEN      23-APR-07     Datafile 1: '/disk1/oradata/prod/system01.dbf' 
                                            contains one or more corrupt blocks
 
analyzing automatic repair options; this may take some time
using channel ORA_DISK_1
analyzing automatic repair options complete
 
Mandatory Manual Actions
========================
no manual actions available
 
Optional Manual Actions
=======================
1. If file /disk1/oradata/prod/users01.dbf was unintentionally renamed or moved, restore it
 
Automated Repair Options
========================
Option Repair Description
------ ------------------
1      Restore and recover datafile 28; Perform block media recovery of 
       block 56416 in file 1
  Strategy: The repair includes complete media recovery with no data loss
  Repair script: /disk1/oracle/log/diag/rdbms/prod/prod/hm/reco_660500184.hm