How to create more copies of Voting Disks in Oracle 11g RAC

You cannot simply add more copies of voting disks to increase redundancy because the number of voting disks is managed by Oracle ASM and determined by the redundancy of the disk group.

To increase the number of voting disks, you need to move them to a disk group with higher redundancy.

So, create the new disk group or identify one that meets your requirements and use the:

crsctl replace votedisk command to move your voting disks to the new disk group.

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Automatic OCR backups

Oracle CRS backs up the OCR automatically at regular intervals.

The standard backup frequency and retention policies are

  • Every 4 hours – keeping the last 3 copies.
  • Every day (at the end) – keeping the last 2 copies.
  • Every week (at the end) – keeping the last 2 copies.

 

You can find the location of the backup as well as which node carries out the backup (only one node backs up the OCR) with the following command:

ocrconfig -showbackup auto

The files may not all be on the node that caries out the backups because of outages.

 

 

 

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Where to find Oracle clusterware log files.

To make administration and problem diagnosis easier in Oracle Clusterware, there is a single consolidated directory structure for the main clusterware log files.

 

This is found under $GRID_HOME/log/[hostname]/

 

The CRSD logfile – crsd.log is stored in the /crsd/ directory and is archived every 10mb.

 

The CSS logfiles – cssd.log is stored in the /cssd/ directory. This is archived every 20mb.

 

EVM logs are under /evmd/

 

SRVM (srvctl) is found along with the OCR logfiles under /client/ and also under $ORACLE_HOME/log/[hostname]/client/

 

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How to enable Clusterware Resource Debugging in Oracle RAC

In order to enable clusterware resource debugging you need to set the resource attribute USR_ORA_DEBUG to 1 for the resource that you wish to debug.

$ crsctl set log res “ora.host01.vip:1”

When you are finished you issue almost the same command to disable the clusterware debugging (set USR_ORA_DEBUG to 0):

$ crsctl set log res “ora.host01.vip:0”

You can also use an initialization file to configure the debugging. This file is located at $GRID_HOME/log/hostname/admin/ and it is names after the process that you are debugging (process_name.ini).

Categories: Oracle Basics, Oracle RAC

How to Check the integrity of OCR files

How to Check the integrity of Oracle Cluster Configuration (OCR) files

To check the health ot OcR files, ther are 3 methods that can be used in unison.

Check for voting disk issues in the ocssd.log with:

grep $GRID_HOME/log/[hostname]/ocssd.log

There are also 2 commands that can help. They are ocrcheck and cluvfy

You run ocrcheck by typing ocrcheck

or clucvy with the following options:

cluvfy comp ocr -n all -verbose

 

Categories: Oracle Basics, Oracle RAC