Thursday, March 17, 2016

[MailServer]: Installing DeepOfix Mail Server

Installing DeepOfix Mail Server

Introduction

DeepOfix is debian based dedicated mail server operating system, which is easy to deploy and not sys admin level expertise are required. It comes with a builtin web based management tool known as easy push server management tool.

Features

Some of the highlighted features are:
  1. LDAP support
The mail server  not only  comes with a builtin LDAP support but also it sores all of the user accounts and mail addresses in LDAP.
2. Anti-Virus and Anti-Spam
No require to configure or manage additional anti virus or anti spam tools as it comes with builtin ClamAV antivirus and spam assassin for spam filtering, both of the tools got updated automatically.
3. Web Based Email
Email can be accesses via internet or on a local network, easy to use web based mail client. User can manger their mail account and passwords.
4. Email Fetch
DeepOfix works with POP3 and IMAC types of multiple protocols,  user can fetch emails from service provider’s server. Single email account can receive emails from multiple users in single inbox.
5.Server Management
Exclusive web based server management or ESM is provided to manage mail accounts, it comes with very rich features including firewall, network,account management, spam control,  server control etc. features which do not require tricky command line skills and a fresher user can also handle their user mail accounts.

Installation

A dedicated server is required with minimum 4 GB RAM, Dual Core Processor with 80 GB of Disk Space. Download the .iso image from here.
Boot system, press enter
mail
Press enter and continue
mail(001)
Accept license agreement press ok to proceed
mail(002)
Make sure you have connected to network, make plan for your domain name, ip address etc and proceed to next step
mail(003)
Select your keyboard format
mail(004)
Select drive in which you are going to make this installation, press enter to proceed
mail(005)
Define your partitions as per need and click next
mail(006)
Accept changes press enter to format disk, press enter to configure network settings in next step
mail(007)
Define IP address in our scenario ip addr will be 192.51.12.222/24
mail(008)
Configure rest of the settings and make sure you have provided proper gate way and dns addresses
mail(014)
Define hostname of system and click next to proceed
mail(015)
Define domain name and, it will be used for email accounts.
mail(016)
For mail server administration we need admin account, define password for admin account
mail(018)
Make sure you have applied all of the settings appropriately
mail(019)
Select your time zone and country:
mail(020)
Press ok, let the installation begin, after reboot you have to login to server via browser
IP_address:4080
mail(022)
mail(022)
login to server to manage mail services.
With easypush email management wizard you can manage all of your email related services
mail(023)
mail(023)
Manage accounts
Click accounts, click on manage groups add a group, let us assume to create a admin group.
mail(024)
mail(024)
Create a mail account in that mail new group, click manage users-> Manage user->click to add user-> provide account details, password and email password warning and password age, make sure warding date must be less then password change date. Along with user email account you can manage all of other contact details also.
mail(025)
mail(025)
Let us test wheather this email address is working or not. Open browser type ip address or domain name and press enter:
mail(027)
mail(027)Login box will appears which indicates that all of the services are working properly.
mail(030)
mail(030)
Explore other management tabs, let us open Server Control Tab, click monitor server and click resource graphs, where you can explore status of running processes
mail(031)
mail(031)
To edit and configure SMTP settings, click to mail server tab, click smtp settings
mail(032)
mail(032)
Similarly you can mange rest of the required settings by your self.

Conclusion:

Deepofix mail server is a must try for users who are seeking a simple and easy to manage stable mail server, as it comes in dedicated os form there is no need to make complicated configurations so that even no technical users can also configure the server very easily.
Have fun!!

Thursday, March 3, 2016

[Quick Tips - Date/Time]: How to set System Date and Time in Linux

How to set System Date and Time in Linux

In this post will show you how to set system date and time on the command prompt in Redhat Linux.  As a first step login to the system as a root user and continue with the below steps to complete the date and time setup. Very important that always in your environment make sure all the system sync with the right date and time each other, if you have an ntp server, will always prefer in high priority to sync your systems with the ntp server, in future post will explain more about ntp in detail.
Step 1: Check the current system date and time by executing the below command in shell prompt
# date
Mon   Sep   28   10:45:11  GMT 2015
Step 2: Syntax to set date
# date   +%D   -s    YYYY-MM-DD
Example
# date   +%D   -s    2015-09-2015
Step 3: Syntax to set time
# date   +%T    -s    HH:MM:SS
Example
# date   +%T    -s    13:50:25
Step 4: Syntax to set date and time in one command
# date   -s    “29  SEP  2015  13:50:25”
or
# date  —-set     “29     SEP    2015      13:50:25     GMT”
Step 5: Check the current status of new date and time
# date
Mon   Sep   29   13:50:25   GMT 2015
In my next post will show you how to sync hardware clock with system time in RedHat Linux.

[SSH- CentOS/ RedHat]: How To Fix: Why SSH Login Takes Long Time to Ask for Password in Redhat Or CentOS

How To Fix: Why SSH Login Takes Long Time to Ask for Password in Redhat Or CentOS


Step 1: Login to Linux machine as a root user. 
[root@linuxsrv ~]#
[root@linuxsrv ~]# cp /etc/ssh/sshd_config /etc/ssh/sshd_config_bkp2015
[root@linuxsrv ~]# sed -i ‘s/#UseDNS yes/UseDNS no/g’ /etc/ssh/sshd_config
[root@linuxsrv ~]# grep -i dns /etc/ssh/sshd_config
UseDNS no
Step 2: Restart sshd service.
[root@linuxsrv ~]# service sshd restart
Stopping sshd: [ OK ]
Starting sshd: [ OK ]
[root@linuxsrv ~]#
[root@linuxsrv ~]#
Step 3:Test the login speed.
[root@linuxsrv ~]# ssh localhost
Warning: Permanently added ‘localhost’ (RSA) to the list of known hosts.
Last login: Thu Oct 8 17:29:57 2015 from 172.10.20.30
[root@linuxsrv ~]#
The above steps helped me to resolve ssh slowness issue, surely it will be helpful for you too if you facesimilar issu

Wednesday, March 2, 2016

[Thin Client - UBUNTU]: Install and Configure Ubuntu LTSP Server

Install and Configure Ubuntu LTSP Server


Introduction

Linux Terminal Server Project or LTSP is a open source project to allow multiple terminal users  to access same resource, Thin clinets will be connected to LTSP server  via LAN network. Thin clients are low powered with no hard disk and lesser processor and RAM configurations are used as thin clients. This Technology is very  cost effective, reliable and cost effective  solution to provide computation facility in Schools and non commercial educational organizations. Thin Clients will be working like full fledged Desktop with GUI without any problem. What we need is a good configuration server which is installed with LTSP enabled Linux Operating System. * GB RAM 80 GB HDD and minimum ci3 processor will be sufficient to run a 15 thin clients lab environments, you can use old cpu with pxe boot support as thin clients.

Features

Cost Effective

With LTSP we can utilize old CPU as Thin clients or we can use new but cost effective TC devices.

No License Required

Running remote service with Microsoft Enterprise servers may cost high, ltsp is a alternative solution wihc is free to use and reliable.

Zero or less maintenance

We can build a complete lab environment using LTSP server and thin clients as they consume lesser power, lesser cooling is required, no Hard disk or heavy processor is required.

Secure

As all users are connected centrally to LTSP server, it is easy to keep watch on users activity. further clients connections can we secured using ssh  service.

Prerequisites and Installation

We need to configure A Ubuntu Alternate Server which can be downloaded fromhttp://www.ubuntu.com/download/alternative-downloads, additionally to assign an automatic IP address to make thin client boot weh will also need to configure DHCP server, make sure that you have installed 02 LAN cards.
Download package
Selection_078

Boot server with Ubuntu alternate .iso image, and press F4
Selection_072
A Menu will appear at the bottom of the screen select Install an LSTP Server option, press enter, select language
Selection_073
Select your location
Selection_074
Press enter and let the installation process begins,  this is to inform you that LTPS settings will authentically configure DHCPserver and there is no need to configure that services additionally, even other services which are required to configure LTSP services will also be loaded automatically.Provide user name and password
Selection_075
Define partitions
Selection_076
Finish partitioning and complete installation process. Configure package manager if required
Selection_077
When Installation is over, create another machine with pxe boot support, we have prepared another virtual box machine for demonstration purpose. Run that machine, press F12, the boot device selection menu will appear. Press “l” to boot from LAN.
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Press enter and let the machine boot,  you can notice that machine will got all of the file systems and IP address from Ubuntu LTSP Server.
Selection_004
Finally thin client system will boot in GUI
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You have a running Thin Client Machine.

Conclusion

Will this LTSP and thin client scenario we can build a cost effective and quick working computing setup which is very cost effective and easy to deploy, no Linux  or Technical experties are require to do that. Have fun!!

[Quick Tips-Terminal_Commands ]: List Of 10 Funny Linux Commands

List Of 10 Funny Linux Commands


Working from the Terminal is really fun. Today, we’ll list really funny Linux commands which will bring smile on your face.

 1. rev

Create a file, type some words in this file, rev command will dump all words written by you in reverse.
# rev  <file name>
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2. fortune

This command is not install by default, install with apt-get and fortune will display some random sentence.
crank@crank-System:~$ sudo apt-get install fortune
Selection_003
Use -s option with fortune, it will limit the out to one sentence.
# fortune -s
Selection_004

3. yes

#yes <string>
This command will keep displaying the string for infinite time until the process is killed by the user.
# yes unixmen
Selection_005

4. figlet

This command can be installed with apt-get, comes with some ascii fonts which are located in /usr/share/figlet.
cd /usr/share/figlet
#figlet -f <font>  <string>
e.g.
#figlet -f big.flf unixmen
Selection_006
#figlet -f block.flf  unixmen
Selection_007
You can try another options also.

5. asciiquarium

This command will transform your terminal in to a Sea Aquarium.
Download term animator
# wget http://search.cpan.org/CPAN/authors/id/K/KB/KBAUCOM/Term-Animation-2.4.tar.gz
Install and Configure above package.
# tar -zxvf Term-Animation-2.4.tar.gz
# cd Term-Animation-2.4/
# perl Makefile.PL && make && make test
# sudo make install
Install following package:
# apt-get install libcurses-perl
Download and install asciiquarium
# wget http://www.robobunny.com/projects/asciiquarium/asciiquarium.tar.gz
# tar -zxvf asciiquarium.tar.gz 
# cd asciiquarium_1.0/
# cp asciiquarium /usr/local/bin/
Run,
# /usr/local/bin/asciiquarium

 asciiquarium_1.1 : perl_008

6. bb

# apt-get install bb
# bb
See what comes out:
Selection_009

 7. sl

Sometimes you type sl instead of ls by mistake,actually  sl is a command and a locomotive engine will start moving if you type sl.
# apt-get install sl
# sl
Selection_012

 8. cowsay

Very common command, is will display in ascii form whatever you wants to say.
apt-get install cowsay
# cowsay <string>
Selection_013
Or, you can use another character instead of com, such characters are stored in/usr/share/cowsay/cows
# cd /usr/share/cowsay/cows
cowsay -f ghostbusters.cow  unixmen
Selection_014or
# cowsay -f bud-frogs.cow Rajneesh
Selection_015

 9. toilet

Yes, this is a command, it dumps ascii strings in colored form to the terminal.
# apt-get install toilet
# toilet --gay unixmen
Selection_016
 toilet -F border -F gay unixmen
Selection_020
toilet  -f mono12 -F metal  unixmen
Selection_018

 10. aafire

Put you terminal on fire with aafire.
# apt-get install libaa-bin
# aafire
Selection_019
That it, Have fun with Linux Terminal!