How to fix error thrown by OPatch: java.lang.NullPointerException

Problem:

Opatch throws the following error when you are querying the inventory:

[oracle@lx01 ~]$ opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.11
Copyright (c) 2015, Oracle Corporation.  All rights reserved.


Oracle Home       : /u01/oracle/product/11.2.0/dbhome_1
Central Inventory : /u01/oraInventory
   from           : /u01/oracle/product/11.2.0/dbhome_1/oraInst.loc
OPatch version    : 11.2.0.3.11
OUI version       : 11.2.0.1.0
Log file location : /u01/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-09-02_08-52-28AM_1.log

Lsinventory Output file location : /u01/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/lsinv/lsinventory2015-09-02_08-52-28AM.txt

--------------------------------------------------------------------------------
java.lang.NullPointerException
 at oracle.sysman.oii.oiin.OiinNetOps.addNICInfo(OiinNetOps.java:144)
 at oracle.sysman.oii.oiin.OiinNetOps.computeNICList(OiinNetOps.java:109)
 at oracle.sysman.oii.oiin.OiinNetOps.(OiinNetOps.java:76)
 at oracle.sysman.oii.oiin.OiinNetOps.getNetOps(OiinNetOps.java:90)
 at oracle.sysman.oii.oiix.OiixNetOps.getFullHostName(OiixNetOps.java:49)
 at oracle.opatch.LsInventoryPrinter.printLocalMachineInfo(LsInventoryPrinter.java:2336)
 at oracle.opatch.LsInventorySession.loadAndPrintInventory(LsInventorySession.java:480)
 at oracle.opatch.LsInventorySession.process(LsInventorySession.java:317)
 at oracle.opatch.OPatchSession.main(OPatchSession.java:2120)
 at oracle.opatch.OPatch.main(OPatch.java:626)
Local Machine Information::
Hostname: lx01.oric.no
ARU platform id: 226
ARU platform description:: Linux x86-64

Installed Top-level Products (1): 

Oracle Database 11g                                                  11.2.0.1.0
There are 1 products installed in this Oracle Home.


There are no Interim patches installed in this Oracle Home.


--------------------------------------------------------------------------------

OPatch succeeded.

Cause:
In my case, the file /etc/hosts was incorrectly configured.

Solution:
Configure the file /etc/hosts correctly.

[root@lx01 ~]# ifconfig 
enp0s3: flags=4163  mtu 1500
        inet 192.168.0.55  netmask 255.255.255.0  broadcast 192.168.0.255

Check the /etc/hosts:

[root@lx01 ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.1.55 lx01.oric.no lx01
[oracle@lx01 ~]$ vi /etc/hosts

Update the incorrect ip address from 192.168.1.55 to 192.168.0.55, and save the file.

Opatch will now display expected output:

[oracle@lx01 ~]$ opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.11
Copyright (c) 2015, Oracle Corporation.  All rights reserved.


Oracle Home       : /u01/oracle/product/11.2.0/dbhome_1
Central Inventory : /u01/oraInventory
   from           : /u01/oracle/product/11.2.0/dbhome_1/oraInst.loc
OPatch version    : 11.2.0.3.11
OUI version       : 11.2.0.1.0
Log file location : /u01/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/opatch2015-09-02_09-07-43AM_1.log

Lsinventory Output file location : /u01/oracle/product/11.2.0/dbhome_1/cfgtoollogs/opatch/lsinv/lsinventory2015-09-02_09-07-43AM.txt

--------------------------------------------------------------------------------
Local Machine Information::
Hostname: lx01.oric.no
ARU platform id: 226
ARU platform description:: Linux x86-64

Installed Top-level Products (1): 

Oracle Database 11g                                                  11.2.0.1.0
There are 1 products installed in this Oracle Home.


There are no Interim patches installed in this Oracle Home.


--------------------------------------------------------------------------------

OPatch succeeded.

How to solve: error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

After a fresh install of an Oracle 32-bit client on a 64-bit Linux server, we received the following errors when we tried to use any of the binaries under the $ORACLE_CLIENT_HOME/bin directory:

 error while loading shared libraries: libaio.so.1: cannot open shared object file: No such file or directory

It turned out that only the 64-bit version of libaio was installed:

yum list libaio
Loaded plugins: product-id, rhnplugin, security
This system is receiving updates from RHN Classic or RHN Satellite.
Installed Packages
libaio.x86_64  0.3.107-10.el6  @anaconda-RedHatEnterpriseLinux-201301301459.x86_64/6.4
Available Packages
libaio.i686  0.3.107-10.el6  prod-rhel-x86_64-server-6

Solution is to simply install the missing package (output abbreviated):

su -
yum install libaio.i686

downloading Packages:
libaio-0.3.107-10.el6.i686.rpm                                                                                                                                                                    |  21 kB     00:00
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
  Installing : libaio-0.3.107-10.el6.i686                                                                                                                                                                            1/1
  Verifying  : libaio-0.3.107-10.el6.i686                                                                                                                                                                            1/1

Installed:
  libaio.i686 0:0.3.107-10.el6

Complete!

How to create a symlink in unix

Syntax:
ln -s /path/physical_file symlink

For example

cd $ORACLE_HOME/lib
ln -s /u01/oracle/product/oracle_client32/lib/libclntsh.so.11.1 libclntsh.so
ls -altr libclntsh.so
libclntsh.so -> /u01/oracle/product/oracle_client32/lib/libclntsh.so.11.1

What does the DEFAULT DEGREE on tables actually mean?

The DOP (degree of parallelism) settings on a table has to do with the number of threads per instance for scanning the table (an integer), or DEFAULT.

When a tables DEGREE setting is set to DEFAULT, it means that the DOP) is calculated via the following formula:

For a single instance:

DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT

For an Oracle RAC configuration:

DOP = PARALLEL_THREADS_PER_CPU x CPU_COUNT x INSTANCE_COUNT

The DOP for a table can be viewed in either of the *_TABLES views.

SELECT DEGREE
FROM   DBA_TABLES
WHERE  TABLE_NAME = 'EMP'
AND    OWNER = 'SCOTT';


DEGREE
------------------
         1

How to use cpio on AIX

I recently received a patch from Oracle support, and when unpacking with unzip, the resulting file was in the cpio format. Unpacking this file, in turn, is done like this:

mkdir install
cd install
cpio -idcmv < 9205_aix5l64_release.cpio

How to create and how to extract a .tar file

Create a tar file of all the files in the current directory:

tar cvf myfile.tar *

or put it in a different directory:

 tar cvf $HOME/myfile.tar *

To extract myfile.tar to the current directory

tar xvf myfile.tar 

To a specific directory:

tar xvf myfile.tar -C mydir

How to solve ORA-17628: Oracle error 19505 returned by remote Oracle server during clone from active database

After some time, my RMAN "duplicate from active database" script threw the error below:

RMAN-03009: failure of backup command on c1 channel at 07/21/2015 12:13:15
ORA-17627: ORA-12577: Message 12577 not found;  product=RDBMS; facility=ORA
RMAN-12019: continuing other job steps, job failed will not be re-run

When I checked the alert log, it was clear

IBM AIX RISC System/6000 Error: 28: No space left on device

Solution: obvious.