ORACLE DATABASE PROBLEM AND SOLUTIONS

Thursday, May 18, 2023

Adding Users to Sudoers in Linux

Login as root user : visudo and check wheel (group) details should be there

## Sudoers allows particular users to run various commands as

## the root user, without needing the root password.

## Examples are provided at the bottom of the file for collections

## of related commands, which can then be delegated out to particular

## users or groups.

## This file must be edited with the 'visudo' command.

## Allows people in group wheel to run all commands

%wheel ALL=(ALL) ALL

## Same thing without a password

# %wheel ALL=(ALL) NOPASSWD: ALL

Login as root user to add user (atharv) in wheel group (sudoers)

[root@0.0.0.0~]# usermod -aG wheel atharv

[root@0.0.0.0~]#

[root@0.0.0.0~]# id atharv

uid=1002(atharv) gid=1002(dba) groups=1002(dba),10(wheel)

[root@0.0.0.0~]#

Login as atharv user

[atharv@0.0.0.0 ~]$ su - atharv

Password:

Last login: Thu May 18 11:50:13 UTC 2023 on pts/1

[atharv@0.0.0.0 ~]$

[atharv@0.0.0.0 ~]$ sudo fdisk -l

Disk /dev/xvda: 60 GiB, 64424509440 bytes, 125829120 sectors

Units: sectors of 1 * 512 = 512 bytes

Sector size (logical/physical): 512 bytes / 512 bytes

I/O size (minimum/optimal): 512 bytes / 512 bytes

Disklabel type: gpt

Disk identifier: 2E431796-24CD-41A3-A4CB-7987FFF67072

Device Start End Sectors Size Type

/dev/xvda1 2048 4095 2048 1M BIOS boot

/dev/xvda2 4096 125829086 125824991 60G Linux filesystem

[atharv@0.0.0.0 ~]$

[atharv@0.0.0.0 ~]$ sudo ls -la /root

total 260816

dr-xr-x---. 9 root root 4096 May 18 11:12 .

dr-xr-xr-x. 21 root root 4096 Jan 13 14:03 ..

-rw-------. 1 root root 6953 May 4 2021 anaconda-ks.cfg

drwx------ 4 root root 27 Apr 14 10:20 .ansible

drwxr-xr-x 3 root root 22 Apr 14 10:14 ansible

-rw-r--r-- 1 root root 77218345 Jan 9 18:30 'AutoDL?BundleId=247937_0ae14417abb444ebb02b9815e2103550'

-rw-r--r-- 1 root root 137320 Feb 18 13:07 aws_replication_agent_installer.log

-rw-r--r-- 1 root root 25289 Feb 6 10:25 aws-replication-installer-init.py

-rw-------. 1 root root 17257 May 18 11:12 .bash_history

-rw-r--r--. 1 root root 18 Aug 12 2018 .bash_logout

-rw-r--r--. 1 root root 176 Aug 12 2018 .bash_profile

-rw-r--r--. 1 root root 176 Aug 12 2018 .bashrc

drwx------ 3 root root 20 Sep 21 2022 .config

drwxr-xr-x 6 root root 95 Sep 21 2022 .cpan

drwxr-xr-x 3 root root 55 Sep 21 2022 .cpanm

-rw-r--r--. 1 root root 100 Aug 12 2018 .cshrc

-rw-r--r-- 1 root root 189609546 Dec 7 23:14 jdk-19_linux-x64_bin.rpm

drwxr-xr-x 3 root root 105 Feb 18 13:01 mgn18022023

-rw-------. 1 root root 0 May 16 17:02 original-ks.cfg

-rw------- 1 root root 3167 Nov 8 2022 .psql_history

drwx------. 2 root root 48 Apr 14 10:25 .ssh

-rw-r--r--. 1 root root 129 Aug 12 2018 .tcshrc

-rw-r--r-- 1 root root 111 May 18 10:44 test.txt

-rw------- 1 root root 1047 May 18 08:41 .viminfo

-rw------- 1 root root 518 May 18 05:50 .Xauthority

[atharv@0.0.0.0 ~]$

How to Add or Remove Linux User From Group : Linux OS

How to Add or Remove Linux User From Group ?

Add the User to a Group in Linux

[root@0.0.0.0~]# usermod -aG wheel atharv

[root@0.0.0.0~]#

[root@0.0.0.0~]# id atharv

uid=1002(atharv) gid=1002(dba) groups=1002(dba),10(wheel)

[root@0.0.0.0~]#

Remove the User from a Group in Linux

[root@0.0.0.0~]#

[root@0.0.0.0~]# gpasswd -d atharv wheel

Removing user atharv from group wheel

[root@0.0.0.0~]#

[root@0.0.0.0~]# id atharv

uid=1002(atharv) gid=1002(dba) groups=1002(dba)

[root@0.0.0.0~]#

Your account has expired; please contact your system administrator : Linux OS

Re-Enable user In Linux : Your account has expired; please contact your system administrator

[atharv@0.0.0.0~]$

[atharv@0.0.0.0~]$ su - atharv

Password:

Your account has expired; please contact your system administrator

su: User account has expired

[atharv@0.0.0.0~]$

[root@0.0.0.0home]# chage -l atharv

Last password change : May 18, 2023

Password expires : never

Password inactive : never

Account expires : May 18, 2023

Minimum number of days between password change : 0

Maximum number of days between password change : 99999

Number of days of warning before password expires : 7

[root@0.0.0.0home]#

[root@0.0.0.0home]# chage --expiredate 2023-05-19 atharv

[root@0.0.0.0home]#

[root@0.0.0.0home]# chage --list atharv

Last password change : May 18, 2023

Password expires : never

Password inactive : never

Account expires : May 19, 2023

Minimum number of days between password change : 0

Maximum number of days between password change : 99999

Number of days of warning before password expires : 7

[root@0.0.0.0home]#

Monday, April 17, 2023

How to get public IP from AWS EC2 instance ?

Use Below command

login as root

curl http://checkip.amazonaws.com

[root@ip-173-11-11-11 ~]#

[root@ip-173-11-11-11~]# curl http://checkip.amazonaws.com

55.2232.1123.123341

[root@ip-173-11-11-11 ~]#

Saturday, April 15, 2023

How to check Ansible version ?

check version of Ansible on Linux

[root@ip-0.0.0.0 project1]#

[root@ip-0.0.0.0 project1]# ansible --version

ansible 2.9.27

config file = /etc/ansible/ansible.cfg

configured module search path = ['/root/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']

ansible python module location = /usr/lib/python3.6/site-packages/ansible

executable location = /usr/bin/ansible

python version = 3.6.8 (default, Jan 11 2023, 08:43:50) [GCC 8.5.0 20210514 (Red Hat 8.5.0-16)]

[root@ip-0.0.0.0 project1]#

How to install Ansible on Linux ?

Install Ansible on Linux OS

=> Login as root user

[root@ip-0.0.0.0 ~]#

[root@ip-0.0.0.0 ~]# yum install ansible

Updating Subscription Management repositories.

Unable to read consumer identity

This system is not registered with an entitlement server. You can use subscription-manager to register.

Last metadata expiration check: 2:49:39 ago on Fri 14 Apr 2023 07:03:14 AM UTC.

Dependencies resolved.

==========================================================================================================================

Package Architecture Version Repository Size

==========================================================================================================================

Installing:

ansible noarch 2.9.27-1.el8ae ansible-2-for-rhel-8-rhui-rpms 17 M

Installing dependencies:

sshpass x86_64 1.09-4.el8 rhel-8-appstream-rhui-rpms 30 k

Installing weak dependencies:

python3-jmespath noarch 0.9.0-11.el8 rhel-8-appstream-rhui-rpms 45 k

Transaction Summary

==========================================================================================================================

Install 3 Packages

Total download size: 17 M

Installed size: 96 M

Is this ok [y/N]: y

Downloading Packages:

(1/3): python3-jmespath-0.9.0-11.el8.noarch.rpm 825 kB/s | 45 kB 00:00

(2/3): sshpass-1.09-4.el8.x86_64.rpm 526 kB/s | 30 kB 00:00

(3/3): ansible-2.9.27-1.el8ae.noarch.rpm 52 MB/s | 17 MB 00:00

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

Total 44 MB/s | 17 MB 00:00

Running transaction check

Transaction check succeeded.

Running transaction test

Transaction test succeeded.

Running transaction

Preparing : 1/1

Installing : sshpass-1.09-4.el8.x86_64 1/3

Installing : python3-jmespath-0.9.0-11.el8.noarch 2/3

Installing : ansible-2.9.27-1.el8ae.noarch 3/3

Running scriptlet: ansible-2.9.27-1.el8ae.noarch 3/3

Verifying : python3-jmespath-0.9.0-11.el8.noarch 1/3

Verifying : sshpass-1.09-4.el8.x86_64 2/3

Verifying : ansible-2.9.27-1.el8ae.noarch 3/3

Installed products updated.

Installed:

ansible-2.9.27-1.el8ae.noarch python3-jmespath-0.9.0-11.el8.noarch sshpass-1.09-4.el8.x86_64

Complete!

[root@ip-0.0.0.0 ~]#

Monday, March 6, 2023

java.lang.UnsupportedClassVersionError: com/dom/benchmarking/swingbench/SwingBench

java.lang.UnsupportedClassVersionError:

[oracle@10.1.0.2 bin]$

[oracle@10.1.0.2 bin]$ ./swingbench

java.lang.UnsupportedClassVersionError: com/dom/benchmarking/swingbench/SwingBench has been compiled by a more recent version of the Java Runtime (class file version 61.0), this version of the Java Runtime only recognizes class file versions up to 52.0

at java.lang.ClassLoader.defineClass1(Native Method)

at java.lang.ClassLoader.defineClass(ClassLoader.java:756)

at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)

at java.net.URLClassLoader.defineClass(URLClassLoader.java:473)

at java.net.URLClassLoader.access$100(URLClassLoader.java:74)

at java.net.URLClassLoader$1.run(URLClassLoader.java:369)

at java.net.URLClassLoader$1.run(URLClassLoader.java:363)

at java.security.AccessController.doPrivileged(Native Method)

at java.net.URLClassLoader.findClass(URLClassLoader.java:362)

at java.lang.ClassLoader.loadClass(ClassLoader.java:418)

at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)

at java.lang.ClassLoader.loadClass(ClassLoader.java:351)

at java.lang.Class.forName0(Native Method)

at java.lang.Class.forName(Class.java:264)

at org.apache.commons.launcher.ChildMain.run(ChildMain.java:183)

[oracle@10.1.0.2 bin]$

[root@10.1.0.2 ~]#

[root@10.1.0.2 ~]# wget https://download.oracle.com/java/19/latest/jdk-19_linux-x64_bin.rpm

--2023-03-06 14:49:06-- https://download.oracle.com/java/19/latest/jdk-19_linux-x64_bin.rpm

Resolving download.oracle.com (download.oracle.com)... 23.56.12.90

Connecting to download.oracle.com (download.oracle.com)|23.56.12.90|:443... connected.

HTTP request sent, awaiting response... 200 OK

Length: 189609546 (181M) [application/x-redhat-package-manager]

Saving to: ‘jdk-19_linux-x64_bin.rpm’

jdk-19_linux-x64_bin.rpm 100%[==================================================>] 180.83M 99.6MB/s in 1.8s

2023-03-06 14:49:08 (99.6 MB/s) - ‘jdk-19_linux-x64_bin.rpm’ saved [189609546/189609546]

[root@10.1.0.2 ~]#

[root@10.1.0.2 ~]# ls -lrt

total 260760

-rw-------. 1 root root 6699 May 4 2021 original-ks.cfg

-rw-------. 1 root root 6953 May 4 2021 anaconda-ks.cfg

-rw-r--r-- 1 root root 189609546 Dec 7 23:14 jdk-19_linux-x64_bin.rpm

-rw-r--r-- 1 root root 77218345 Jan 9 18:30 'AutoDL?BundleId=247937_0ae14417abb444ebb02b9815e2103550'

-rw-r--r-- 1 root root 25289 Feb 6 10:25 aws-replication-installer-init.py

drwxr-xr-x 3 root root 105 Feb 18 13:01 mgn18022023

-rw-r--r-- 1 root root 137320 Feb 18 13:07 aws_replication_agent_installer.log

[root@10.1.0.2 ~]#

[root@10.1.0.2 ~]# rpm -Uvh jdk-19_linux-x64_bin.rpm

warning: jdk-19_linux-x64_bin.rpm: Header V3 RSA/SHA256 Signature, key ID ec551f03: NOKEY

Verifying... ################################# [100%]

Preparing... ################################# [100%]

Updating / installing...

1:jdk-19-2000:19.0.2-7 ################################# [100%]

[root@10.1.0.2 ~]#

[root@10.1.0.2 ~]# which java

/usr/bin/java

[root@10.1.0.2 ~]#

[root@10.1.0.2 ~]# java -version

java version "19.0.2" 2023-01-17

Java(TM) SE Runtime Environment (build 19.0.2+7-44)

Java HotSpot(TM) 64-Bit Server VM (build 19.0.2+7-44, mixed mode, sharing)

[root@10.1.0.2 ~]#

workaround :

We have to install compatible java version so that application software (swingbench) run