How to Update CentOS IP and Hostname via Bash Script

I have created below mentioned bash script which will help you to update the IP Address and the hostname of the CentOS machines via this bash script.

#!/bin/bash

read -p "Enter the new IP address i.e: 10.50.4.243/20 : " ip_address

read -p "Enter the new gateway i.e:- 10.50.0.1 : " gateway

read -p "Enter the new hostname i.e: co7-50-4-243 : " hostname

# Get the interface name

interface=$(ip route | awk '/default/ { print $5 }')

# Get the ip address

ipa=$(hostname -I | awk '{ print $1 }')

# Update the IP address and gateway

echo "Updating IP address and gateway..."

nmcli con mod "$interface" ipv4.address "$ip_address"

nmcli con mod "$interface" ipv4.gateway "$gateway"

# Update the hostname

echo "Updating hostname..."

hostnamectl set-hostname "$hostname"

# Update the /etc/hosts file

echo "Updating /etc/hosts file..."

echo "$ipa $hostname" >> /etc/hosts

# Restart the network service

echo "Restarting network service..."

systemctl restart NetworkManager

echo "IP address, gateway, hostname, and /etc/hosts file updated successfully."

Starting and Stopping Oracle Service in Linux

Starting Oracle

login as: root on your oracle installed system

To verify service and ports are listening up check with these commands

[root@CENTOS ~]# netstat -ntpul | grep :1521



[root@CENTOS ~]# netstat -ntpul | grep :1522



Then switch to oracle user for starting services

[root@CENTOS ~]# su - oracle



Then start services with these command

[oracle@CENTOS ~]$ lsnrctl start

The command completed successfully

Then run this command

[oracle@CENTOS ~]$ sqlplus



Then run this command

Enter user-name: sys as sysdba

Enter password: mind123

Connected to an idle instance.

SQL> startup

quit command from exit from sql console

SQL> quit

Run this command to start web interface console to manage Oracle database

[oracle@CENTOS ~]$ emctl start dbconsole

Starting Oracle Enterprise Manager 11g Database Control............. started.

---

Shutdown Oracle Database

To shutdown Oracle server use this command.

[oracle@CENTOS ~]$ sqlplus

Then run this command

Enter user-name: sys as sysdba

Enter password: mind123

Connected to an idle instance.

SQL> shutdown immediate

select TABLE_NAME,TABLESPACE_NAME,STATUS,NUM_ROWS,AVG_ROW_LEN,BLOCKS,EMPTY_BLOCKS from SYS.USER_TABLES WHERE TABLE_NAME LIKE '%RULE_SET*%';

How to install XenCenter on Linux

Install OpenXenManager on Debian or Ubuntu

 $ sudo apt-get install git python-gtk2 glade python-gtk-vnc python-glade2 python-configobj
 $ git clone https://github.com/OpenXenManager/openxenmanager.git
 $ cd openxenmanager
 $ sudo python setup.py install

Install OpenXenManager on CentOS, Fedora or RHEL

$ sudo yum install pygtk2 gtk-vnc-python rrdtool
$ git clone https://github.com/OpenXenManager/openxenmanager.git
$ cd openxenmanager
$ sudo python setup.py install

Manage XenServer Host Remotely with OpenXenManager

To launch OpenXenManager, just type the following command:

$ openxenmanager

Connect to a remote XenServer host by clicking on "Add New Server" button on the top.