Thursday, September 29, 2016

How to recreate oraInventory using Oracle Universal Installer (OUI)

I come across the missing oraInventory issue and I have recreated the inventory using Oracle Universal installer. In case inventory got corrupted, you can use the same steps.

1. Make sure you set the ORACLE_HOME variable
$ export ORACLE_HOME=/oracle/product/11203

2. Update the $ORACLE_HOME/oraInst.loc file to point to the inventory or wherever you want to keep the inventory.

Forex:- cat $ORACLE_HOME/oraInst.loc

3. Run below OUI command to register ORACLE_HOME

$cd $ORACLE_HOME/oui/bin
$ ./runInstaller -silent -invPtrLoc $ORACLE_HOME/oraInst.loc -attachHome ORACLE_HOME="/oracle/product/11203" ORACLE_HOME_NAME="OraDb11g_home1"

In case of RAC environment, pls use below syntax

$./runInstaller -silent -attachHome oracle_home="<oracle_home_location>"
"cluster_nodes={<node1, node2>}" local_node="<node_name>"

4. You can verify the inventory created or not using below command
$ORACLE_HOME/OPatch/opatch lsinventory -invPtrLoc $ORACLE_HOME/oraInst.loc

Deleting Oracle Home from Central Inventory
$./runInstaller -silent -detachHome -invPtrLoc $ORACLE_HOME/oraInst.loc 

Satishbabu Gunukula, Oracle ACE

Thursday, September 22, 2016

Explore Oracle Database In-Memory in 12C – Part1

Hi Everyone,

It’s been couple of months that I published my last article. Finally I was able to find some time and published new article in Oracle Experts website media "" by RedGate

In this article I will cover:

·         Oracle In-Memory Dual-Format Architecture
·         In-Memory Column Store
·         In-Memory Column Store Restrictions
·         How to enable In-Memory Column Store

Please view the article using below link.
Explore Oracle Database In-Memory – Part1

You will see more articles on this topic in near future.

This article will help users to understand In-Memory architecture, benefits, restrictions, functionality, performance…etc.

I hope you like the article and it will be helpful to you.

Please leave your valuable comments.

Satishbabu Gunukula, Oracle ACE

Thursday, September 8, 2016

InnoDB: Unable to lock ./ib_logfile0, error: 11

One of our MySQL servers got restarted and after restart MySQL instance was not coming online.

I see below error message in mysqld.log

InnoDB: Unable to lock ./ib_logfile0, error: 11
InnoDB: Check that you do not already have another mysqld process
InnoDB: using the same InnoDB data or log files.
InnoDB: Error in opening ./ib_logfile0
160712 19:16:34 [ERROR] Plugin 'InnoDB' init function returned error.
160712 19:16:34 [ERROR] Plugin 'InnoDB' registration as a STORAGE ENGINE failed.
160712 19:16:34 [ERROR] Unknown/unsupported storage engine: InnoDB
160712 19:16:34 [ERROR] Aborting
160712 19:16:34 [Note] /u01/mysql/5.5.22/bin/mysqld: Shutdown complete

I receive below error message when trying to access the database from command line

# mysql -u root -p
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/u01/mysql/5.5.22/mysqld.sock' (2) 

It looks like the sudden server crash didn’t update the logfile or datafile header properly and not able to lock to bring the instance up.

After research I was able to fix this error by following below steps

1. Go to the data directory and backup the ./ib_logfile0 and copy a new one
$ mv ib_logfile0 ib_logfile0.bak
$ cp -a ib_logfile0.bak ib_logfile0

2. Restart the mySQL database

Satishbabu Gunukula, Oracle ACE