[Video] [HowTo] CentOS / RHEL 7 Installation with GUI / Custom Partition


Today I have tried to Install CentOS 7 on my Virtual Machine. Sharing video of CentOS 7 Installation with GUI and Custom Partition with LVM.

Hope this video will help to those who wants to Install and Looking for easy guide for CentOS 7 Installation.

CentOS / RHEL 7 Installation Video

Enjoy CentOS 7 🙂 Enjoy RHEL 7 🙂 Enjoy Linux 🙂 Enjoy Open Source 🙂

Please Keep in Touch with Social Networking :- 
Facebook Page :- https://www.facebook.com/AllLinuxUsersBlog

RHEL 7 / CentOS 7 : How to get started with Systemd

Hello All,

Today I was trying to learn and know about Systemd. I have found one of the great Article, Sharing with you guys, It will help you to understand this biggest and major change in RHEL and CentOS 7.

This article is not mine, I found on internet and felt that this is wonderful Article so Sharing with you all, Thanks to Original author, Given credit to him at the end of article.


RHEL / CentOS systemD
RHEL / CentOS systemD


As the Systemd now replaces SysVinit, it is time to get familiar with it and learn new commands.
Systemd is quicker because it uses fewer scripts and tries to run more tasks in parallel (Systemd calls them units).
The Systemd configuration is stored in the /etc/systemd directory.

Boot process

Systemd primary task is to manage the boot process and provides informations about it.
To get the boot process duration, type:

# systemd-analyze
Startup finished in 422ms (kernel) + 2.722s (initrd) + 9.674s (userspace) = 12.820s

To get the time spent by each task during the boot process, type:

# systemd-analyze blame
7.029s network.service
2.241s plymouth-start.service
1.293s kdump.service
1.156s plymouth-quit-wait.service
1.048s firewalld.service
632ms postfix.service
621ms tuned.service
460ms iprupdate.service
446ms iprinit.service
344ms accounts-daemon.service
7ms systemd-update-utmp-runlevel.service
5ms systemd-random-seed.service
5ms sys-kernel-config.mount

Note: You will find additional information on this point in the Lennart Poettering’s blog.

Journal analysis

In addition, Systemd handles the system event log, a syslog daemon is not mandatory any more.
To get the content of the Systemd journal, type:

# journalctl

To get all the events related to the crond process in the journal, type:

# journalctl /sbin/crond

Note: You can replace /sbin/crond by `which crond`.

To get all the events since the last boot, type:

# journalctl -b

To get all the events that appeared today in the journal, type:

# journalctl --since=today

To get all the events with a syslog priority of err, type:

# journalctl -p err

To get the 10 last events and wait for any new one (like “tail -f /var/Log/messages”), type:

# journalctl -f

Note: You will find additional information on this point in the Lennart Poettering’s blog or Lennart Poettering’s video (44min: the first ten minutes are very interesting concerning security issues).

Control groups

Systemd organizes tasks in control groups. For example, all the processes started by an apache webserver will be in the same control group, CGI scripts included.

To get the full hierarchy of control groups, type:

# systemd-cgls
│ └─user-1000.slice
│ └─session-1.scope
│ ├─2889 gdm-session-worker [pam/gdm-password]
│ ├─2899 /usr/bin/gnome-keyring-daemon --daemonize --login
│ ├─2901 gnome-session --session gnome-classic
. .
└─785 /sbin/iprupdate --daemon

To get the list of control group ordered by CPU, memory and disk I/O load, type:

# systemd-cgtop
Path Tasks %CPU Memory Input/s Output/s
/ 213 3.9 829.7M - -
/system.slice 1 - - - -
/system.slice/ModemManager.service 1 - - - -

To kill all the processes associated with an apache server (CGI scripts included), type:

# systemctl kill httpd

To put resource limits on a service (here 500 CPUShares), type:

# systemctl set-property httpd.service CPUShares=500

Note1: The change is written into the service unit file. Use the –runtime option to avoid this behavior.
Note2: By default, each service owns 1024 CPUShares. Nothing prevents you from giving a value smaller or bigger.

To get the current CPUShares service value, type:

# systemctl show -p CPUShares httpd.service

Sources: New control group interface, Systemd 205 announcement.

Service management

Systemd deals with all the aspects of the service management. The systemctl command replaces the chkconfig and the service commands. The old commands are now a link to the systemctl command.

To activate the NTP service at boot, type:

# systemctl enable ntpd

Note1: You should specify ntpd.service but by default the .service suffix will be added.
Note2: If you specify a path, the .mount suffix will be added.
Note3: If you mention a device, the .device suffix will be added.

To deactivate it, start it, stop it, restart it, reload it, type:

# systemctl disable ntpd
# systemctl start ntpd
# systemctl stop ntpd
# systemctl restart ntpd
# systemctl reload ntpd

To know if the NTP service is activated at boot, type:

# systemctl is-enabled ntpd

To know if the NTP service is running, type:

# systemctl is-active ntpd

To get the status of the NTP service, type:

# systemctl status ntpd
   Loaded: not-found (Reason: No such file or directory)
   Active: inactive (dead)

If you change a service configuration, you will need to reload it:

# systemctl daemon-reload

To get the list of all the units (services, mount points, devices) with their status and description, type:

# systemctl

To get a more readable list, type:

# systemctl list-unit-files

To get the list of services that failed at boot, type:

# systemctl --failed

To get the status of a process (here httpd) on a remote server (here rhel7.example.com), type:

# systemctl -H root@rhel7.example.com status httpd.service

Run levels

Systemd also deals with run levels. As everything is represented by files in Systemd, target files replace run levels.

To move to single user mode, type:

# systemctl rescue

To move to the level 3 (equivalent to the previous level 3), type:

# systemctl isolate runlevel3.target


# systemctl isolate multi-user.target

To move to the graphical level (equivalent to the previous level 5), type:

# systemctl isolate graphical.target

To set the default run level to non-graphical mode, type:

# systemctl set-default multi-user.target

To set the default run level to graphical mode, type:

# systemctl set-default graphical.target

To get the current default run level, type:

# systemctl get-default

To stop a server, type:

# systemctl poweroff

Note: You can still use the poweroff command, a link to the systemctl command has been created (the same thing is true for the halt and reboot commands).

To reboot a server, suspend it or put it into hibernation, type:

# systemctl reboot
# systemctl suspend
# systemctl hibernate

Linux standardization

Systemd‘s authors have decided to help Linux standardization among distributions. Through Systemd, changes happen in the localization of some configuration files.


To get the server hostnames, type:

# hostnamectl
Static hostname: rhel7.example.com
Icon name: computer-laptop
Chassis: laptop
Machine ID: bcdc71f1943f4d859aa37e54a422938d
Boot ID: f84556924b4e4bbf9c4a82fef4ac26d0
Operating System: Red Hat Enterprise Linux Everything 7.0 (Maipo)
CPE OS Name: cpe:/o:redhat:enterprise_linux:7.0:beta:everything
Kernel: Linux 3.10.0-54.0.1.el7.x86_64
Architecture: x86_64

Note: There are three kinds of hostnames: static, pretty, and transient.
“The static host name is the traditional hostname, which can be chosen by the user, and is stored in the /etc/hostname file. The “transient” hostname is a dynamic host name maintained by the kernel. It is initialized to the static host name by default, whose value defaults to “localhost”. It can be changed by DHCP or mDNS at runtime. The pretty hostname is a free-form UTF8 host name for presentation to the user.” Source: RHEL 7 Networking Guide.

To assign the rhel7 hostname permanently to the server, type:

# hostnamectl set-hostname rhel7

Note: With this syntax all three hostnames (static, pretty, and transient) take the rhel7 value at the same time. However, it is possible to set the three hostnames separately by using the –pretty, –static, and –transient options.

To get the current locale, virtual console keymap and X11 layout, type:

# localectl
System Locale: LANG=en_US.UTF-8
VC Keymap: en_US
X11 Layout: en_US

To assign the en_GB.utf8 value to the locale, type:

# localectl set-locale LANG=en_GB.utf8

To assign the en_GB value to the virtual console keymap, type:

# localectl set-keymap en_GB

To assign the en_GB value to the X11 layout, type:

# localectl set-x11-keymap en_GB

To get the current date and time, type:

# timedatectl
Local time: Fri 2014-01-24 22:34:05 CET
Universal time: Fri 2014-01-24 21:34:05 UTC
RTC time: Fri 2014-01-24 21:34:05
Timezone: Europe/Madrid (CET, +0100)
NTP enabled: yes
NTP synchronized: yes
RTC in local TZ: no
DST active: no
Last DST change: DST ended at
Sun 2013-10-27 02:59:59 CEST
Sun 2013-10-27 02:00:00 CET
Next DST change: DST begins (the clock jumps one hour forward) at
Sun 2014-03-30 01:59:59 CET
Sun 2014-03-30 03:00:00 CEST

To set the current date, type:

# timedatectl set-time YYYY-MM-DD

To set the current time, type:

# timedatectl set-time HH:MM:SS

To get the list of time zones, type:

# timedatectl list-timezones

To change the time zone to America/New_York, type:

# timedatectl set-timezone America/New_York

To get the users’ list, type:

# loginctl list-users
42 gdm
1000 tom
0 root

To get the list of all current user sessions, type:

# loginctl list-sessions
1 1000 tom seat0

1 sessions listed.

To get the properties of the user tom, type:

# loginctl show-user tom
Timestamp=Fri 2014-01-24 21:53:43 CET

For a better understanding, you can additionally read Bob Cromwell’s blog about Systemd.

Thanks to Original Author for explaining it very nicely.

Source : http://www.certdepot.net/rhel7-get-started-systemd/

Enjoy Systemd 🙂 Enjoy RHEL 7 🙂 Enjoy CentOS 7 🙂 Enjoy

Please Keep in Touch with Social Networking :- 
Facebook Page :- https://www.facebook.com/AllLinuxUsersBlog

Download CentOS 7 ISO / DVD / x86_64 / i386 / 32-Bit / 64-Bit


NOTE: Sorry for misleading title, There jo 32-Bit version available for CentOS 7!

Hello and welcome to the first CentOS-7 release. CentOS is an Enterprise-class Linux Distribution derived from sources freely provided to the public by Red Hat1.

CentOS conforms fully with Red Hat’s redistribution policy and aims to have full functional compatibility with the upstream product. CentOS mainly changes packages to remove Red Hat’s branding and artwork.

We have decided not to follow Red Hat’s usage of Installation Codes. All ‘channels’ are available to the System Administrator at time of installation.


For the first time, there is a supported upgrade path from CentOS-6 to CentOS-7. This path is only supported from the latest version of CentOS-6 (being 6.5 at the time of writing) to the latest version of CentOS-7. For more information on the upgrade procedure please take a look at this page. The tools needed for this functionality are still being tested and will be released at a later time. If you can help with the testing, please see this CentOS-Devel mailing list thread.

Link to Download CentOS 7 :- http://www.centos.org/download/

Please Keep in Touch with Social Networking :- 
Facebook Page :- https://www.facebook.com/AllLinuxUsersBlog

Script for Check Bulk IP Ping / Status / Health | Linux


Sharing Basic script which I have shared in Some LUG before few months.

Sharing it here because it will help to people who wants to check PING of Bulk IP Addresses and check status and health by pinging the IP Address.

Again repeating this is very basic script and many changes required to improve, You can suggest me or you can send me improve one so i will update it over here. Your Suggestions are always welcome.

Requirements to run Script :-
1. One File which contains all IPs. One IP per line.
2. If you have different class, From system which you are running this script must contact those hosts. Routing must be through to get ping.
# Below is example file. which is containing IP List
[root@tejas-barot-lenovo ~]# cat /root/ping.txt
#Below is script which will helps you. Script is not dynamic with variable and all
[root@tejas-barot-lenovo ~]# cat /root/ping.sh
####### Script Starts from here ######
# -c3 = is ping count, It will ping for 3 times, You can increase or decrease this number.
for PNG in $(cat /root/ping.txt)
ping -c3 $PNG > /dev/null 2>&1
if [ $VAL = 0 ] ; then
echo “Success Ping… Host $PNG is up”
echo “No Ping…Host $PNG is Down”
##### Script Ends here ##
You can also you fping :
As Normal User, fping will not allow you to specify -f, -f is allowed for root only.
As a Normal user you can try, even as root you can try following :-
$ fping < <file-name-with-ips>

# fping < <file-name-with-ips>

Hope this will helps you.
Enjoy Linux 🙂 Enjoy Scripting 🙂  Enjoy Open Source 🙂

Please Keep in Touch with Social Networking :- 
Facebook Page :- https://www.facebook.com/AllLinuxUsersBlog

Thank You India for making Narendra Modi as Prime Minister of India

Hello All,

Firstly I would like to Congratulate Shri Narendra Modi for becoming Next Prime Minister of India.

This Election was special, tough and very Surprising for not only Political parties but also People of India. Specially This election was toughest for BJP as BJP was struggling to get into the power from Last 10 years, But i will not go much in detail about politics.

I want to Thank You India and Specially want to Thank India for Rejecting “Communalism Vs Secularism, Anarchists, Anti Nationalists, Negative Campaigning and many more”. Other side I want to thank Shri Narendra Modi and BJP for sticking to Development and Governance agenda in this election. Congratulations to BJP and Narendra Modi for getting Positive Mandate of India.

I am quickly moving on to the Subject and I want to Thank People of India for Electing Narendra Modi as Prime Minister of India. What more important is People of India elected Shri Narendra Modi smartly and with huge responsibility, After 30 years People of India given Clear Mandate, Given Majority to BJP and more than 50% seats to Only BJP and NDA is 330+ seats. So India chosen Strongest government after 30 years.

Prime Minister of India
Prime Minister of India

I want to Thank People of India for giving Majority to Shri Narendra Modi and BJP. Strong government for India was Much needed and I am very happy that People of India understood this very well and choosing Modi/BJP clearly, We have seen governments from last 30 years with inside or outside support which obviously stops and develops India slowly.

This Government is now in Clear Majority and This government will not work in any pressure and More importantly We have Narendra Modi as Prime Minister of India who is very well known for Development, Good Governance, Decision maker and quick decision maker. Now I am very sure that One India will be Best India and Developed India.

Being Gujarati I have seen Development and Governance under Shri Narendra Modi in Gujarat as Chief Minister and I want to assure people of India that You will never feel that you have voted for wrong person, This person will make your Vote’s value count and will make “Bhavya and Divya Bharat“.

In just few years, I am sure we will proudly say that “Every Part of India is Secure, India is Developed, We have the best Governance, We have PM who takes quick and right Decisions”.

One more time, Thank You India for Making Narendra Modi as Prime Minister of India and Voted for Governance and Development. CongratsNamo.

Last but not the Least, I want to Congratulate campaigning and advertising team of BJP for doing positive campaign like “Achche Din Aane walen Hain”, “Ab Ki Baar Modi Sarkaar”.

Victory Speech of Prime Minister of India from Ahmedabad :-


Disable / Password Protect Single User Mode / RHEL / CentOS / 5.x / 6.x

Hello All,

If you have not protected Single User Mode with Password then it is big risk for your Linux Server, So protecting Single User Mode with Password is very important when it comes to security,

Today in this article i will show you how you can protect Single User Mode with Password on RHEL / CentOS 5.x and RHEL / CentOS 6.x.

Please execute given commands carefully else your system will not boot properly. First i would request you to read full procedure and then try to follow. Do it at your own risk 🙂


Password Protect
Password Protect


1. For RHEL / CentOS 5.x

1.1 Before doing anything please take backup of your /etc/inittab

cp /etc/inittab /etc/inittab.backup

To Disable and Make Single User Mode Password Protected, Execute below command as root :-

[root@tejas-barot-linux ~]$ sed -i '1i  su:S:wait:/sbin/sulogin'

So It will look like below

# Default runlevel. The runlevels used by RHS are:
# 0 - halt (Do NOT set initdefault to this)
# 1 - Single user mode
# 2 - Multiuser, without NFS (The same as 3, if you do not have networking)
# 3 - Full multiuser mode
# 4 - unused
# 5 - X11
# 6 - reboot (Do NOT set initdefault to this)

NOTE: If you do not want to use sed command then You can always add “su:S:wait:/sbin/sulogin” at top in /etc/inittab

2. For RHEL / CentOS 6.x

2.1 Before doing anything please take backup of your /etc/inittab

cp /etc/sysconfig/init /etc/sysconfig/init.backup

2.2 To Disable and Make Single User Mode Password Protected, Execute below command as root :-

[root@tejas-barot-linux ~]$#sed -i 's/SINGLE=\/sbin\/sushell/SINGLE=\/sbin\/sulogin/' /etc/sysconfig/init

So It will look like below


NOTE :- If you do not want to use sed command then You can always change to “SINGLE=/sbin/sulogin” in /etc/sysconfig/init

Enjoy Linux 🙂 Enjoy Open Source

Please Keep in Touch with Social Networking :- 
Facebook Page :- https://www.facebook.com/AllLinuxUsersBlog