Diagnose RAC Problems

Common problems:

• Check RAC network configuration and Network Time Protocol (NTP) synchronization..
• Incorrect shared storage configuration can cause RAC to fail.
• All prerequisites must be installed before starting installation of an Oracle RAC.
• Make sure that you have sufficient disk space, RAM, CPU, and so on.

Clusterware log directory hierarchy:

Check the current status of all the resources using the following command:

crsctl status resource -t

Display top-level view of the cluster:

crsctl check cluster -all

Check the CRS status with the following command:

crsctl check crs

These commands can be executed by root user, grid (GI owner), and Oracle (RAC owner).

Disable or enable all the CRSDs:

crsctl disable crs crsctl enable crs

List the OCR and its mirrors:

ocrcheck

Dump the contents of the OCR to a .txt or .xml file:

# Text file ocrdump file.txt # XML format ocrdump –stdout -xml # OCR backup file ocrdump –backupfile file.ocr

The OCR is backed up automatically every four hours on at least one of the nodes in the cluster.

The backups are stored in the $GRID_HOME/cdata/<cluster_name> directory.

To show the backup information, use this command:

ocrconfig -showbackup

Use the following command to check the voting disk location:

crsctl query css votedisk

Check the SCAN configuration of the cluster:

srvctl config scan

Check the SCAN configuration of the cluster:

srvctl config scan

Check the node apps:

srvctl status nodeapps

Cluster Health Check with CVU:

cluvfy comp healthcheck –collect cluster –bestpractice -html The cluvfy utility supports the following arguments: -collect cluster|database -bestpractices|-mandatory|-deviations -save –savedir    --to save the output under a particular location -html      --output will be written in an HTML file

ORAchk - Health Checks for the Oracle Stack (Doc ID 1268927.2):

$ mkdir orachk $ unzip -d orachk orachk.zip $ cd orachk $ ./orachk CRS stack is running and CRS_HOME is not set. Do you want to set CRS_HOME to /u01/app/12.1.0.1/grid?[y/n][y] Checking ssh user equivalency settings on all nodes in cluster Node rac2 is configured for ssh user equivalency for oracle user Searching for running databases . . . . . . . List of running databases registered in OCR 1. bkisdb 2. None of above Select databases from list for checking best practices. For multiple databases, select 1 for All or comma separated number like 1,2 etc [1-2][1].1 . . Checking Status of Oracle Software Stack - Clusterware, ASM, RDBMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -------------------------------------------------------------------------------------------------------                                                 Oracle Stack Status                             ------------------------------------------------------------------------------------------------------- Host Name  CRS Installed  ASM HOME       RDBMS Installed  CRS UP    ASM UP    RDBMS UP  DB Instance Name ------------------------------------------------------------------------------------------------------- rac1 Yes             N/A             Yes             Yes        Yes      Yes         rac2 Yes             N/A             Yes             Yes        Yes      Yes        --------------------------------------------------------------------------------------- . . [output truncated]

I hope this helps.

Please feel free to leave your questions or suggest improvements to this section.