802.11 Enhancements

Before we move on, it’s important to note that B, G, and N are not the only extensions. It would make sense to start with Wireless A, right? That actually does exist. However, these other protocols either did not catch on as fast as others or serve a purpose other than for home networks. For example, Wireless A was released around the same time as Wireless B. However, Wireless B devices were cheaper so they were more popular with consumers. Wireless A devices were mainly used by businesses. So that’s why you won’t hear much about those while you shop for wireless routers for your home network today. If you’re still curious about these “other” standards, you can find good information about them by doing a quick search. Wikipedia has some good information about them, but it’s pretty technical so look out for that! Lets move on.

802.11B / What Is Wireless B?

Routers with only Wireless B are no longer manufactured. However, some newer routers still support wireless B. So, it’s still important that you have some basic information about it. Wireless B supports a maximum theoretical transfer rate of 11mbps. The signal is good for up to about 150 feet. A downside to a Wireless B device is that it operates at the unregulated 2.4GHz frequency range. This is the same as many common household appliances. Things like cordless phones and microwaves can cause interference if your router is near these appliances. If you don’t place your router or computer near one of these appliances, you should be fine.

802.11G / What Is Wireless G?

Wireless G supports a maximum theoretical transfer rate of 54mbps. Like Wireless B, it operates at the unregulated 2.4GHz frequency range. So it has the same interference issues that Wireless B has. Wireless G is backward compatible with Wireless B devices. Odds are that you don’t have a device that only supports Wireless B, but if you do then this is a benefit. As you can see, the main benefit of a Wireless G router over a Wireless B router is speed.

802.11N / What Is Wireless N?

Wireless N supports a maximum theoretical transfer rate of 300mbps with 2 antennas. It can reach up to 450mbps with 3 antennas. Though typical speeds are more accurately around 130mbps or less without certain configurations and conditions being met. There will be a detailed post on this in the future. If you are curious, please subscribe to this blog and you will be notified when that post comes. It operates at both the 2.4GHz and 5GHz bands. These Wireless N devices can operate on multiple signals (called Multiple In – Multiple Out… or MIMO) and have 2 or 3 antennas. It also has increased signal range/power over Wireless G.

802.11AC / What Is Wireless AC?

The next big standard to hit the world is 802.11ac, or Wireless AC. While it is not finalized yet, there are a significant amount of routers available that use Wireless AC. It is expected to be finalized in 2014. Wireless AC is sometimes referred to as Gigabit WiFi (1Gbps… 1 GigaBit Per Second). It will also have stronger signal strength than Wireless N, giving it greater coverage area. If you are looking for the latest edge in speed, or if you have a Wireless N router that doesn’t quite cover your whole home, you may want to consider a Wireless AC router.

Wireless G vs N, Wireless AC vs N: Which One Should I Buy?

The real choice here is going to be Wireless G vs N vs AC, because routers that only support Wireless B are no longer manufactured. Besides, Wireless G routers are backward compatible with Wireless B devices.

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This tutorial will describes how to upgrade Ubuntu Server 12.04.x to Ubuntu Server 14.04 LTS. As we know, Ubuntu Server 14.04 is the latest version of ubuntu server edition that released by canonical few month ago.

NOTE : Before starting upgrade to latest version of ubuntu server, make sure you have full backups you data and everything important on your ubuntu server to other remote system or backup drive. If you are using Ubuntu on VPS make sure take a server snapshot at your provider before upgrading. And we do not grantees the following tutorial will work for you properly.

Step 1: 

Updating Ubuntu Repository and Install Update Manager

Make sure your current ubuntu server  is fully up to date, doing it with the following command:

sudo apt-get update

Install update manager core package with these command:

sudo apt-get install update-manager-core

Step 2: 

Check Current Version of Ubuntu Server and Kernel Version

Run the following command to check current version of ubuntu server and kernel information that used ubuntu server

lsb_release -a

uname -a

On this case, we are using Ubuntu Server 12.04.4 and kernel 3.8.0-29-generic

Step 3: Upgrade to Ubuntu Server 14.04 LTS

Type the following command to upgrade the Ubuntu server 12.04.4 to Ubuntu Server 14.04 LTS :

sudo do-release-upgrade -d

After execute command do-release-upgrade, it will showing the upgrade tool like the screenshot on below. Answer ” Y ” to upgrade.

During the upgrade prosess, you may be asked “Disable SSH password authentication for root?” answer “No” if you want to disable SSH password authentication after the upgrading finish

Next, you may be asked “Restart services during package upgrades without asking?” answer yes if you won’t be asked on each library update.

The end of the installation you will be prompted to remove any obsolete packages, Answer ‘y’ to continue and remove. Hit ‘d’ to see details of these packages.

Once remove obsolete packages is complete, you will get message “System upgrade is complete”. Congratulations, your Ubuntu Server 12.04 has now been upgraded to the Ubuntu Server 14.04 LTS. To complete the upgrade, reboot your Ubuntu Server by answering ‘Y’.

Step 4 : Checking Version of Ubuntu Server and Kernel Version After Upgrade

Once your Ubuntu Server has been rebooted successfully, you need to check the version of ubuntu server and kernel version with the command “lsb_release -a” and “uname -r”.

lsb_release -a

uname -r

The commands will confirm the Ubuntu Server that you are using is Ubuntu Server 14.04 LTS.

Optional: If you get information “No LSB modules are available ” after execute the command “lsb_release -a” . Fix this problem by installing “lsb_core” package:

sudo apt-get update

sudo apt-get install lsb-core

Now run again the command lsb_release -a to check for LSB modules. You should get information of LSB version like the following screenshot.

lsb_release a

On this tutorial we also included video step by step upgrading ubuntu server 12.04 to ubuntu server 14.04. The following video created by LinuxScoop, original video can found here

Link Reference:

• Upgrading Ubuntu Server

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Upgrade Ubuntu 12.04 LTS to Ubuntu 14.04 LTS

First things first: make sure that you are fully up-to-date. Double check by opening the Update Manager application from the dash and installing all updates listed.

When that’s done, open the Dash again and launch the Terminal application. When it opens click inside the window and type the following command carefully:

sudo update-manager -d

Hit the return/enter key and, if prompted, enter your user password.

The Update Manager application will open after a few seconds with a prompt to upgrade. Click this button to begin the process.

I tested this just now.

$ lsb_release -a

No LSB modules are available.

Distributor ID: Ubuntu

Description: Ubuntu 12.04.5 LTS

Release: 12.04 Codename: precise

Then:

$ sudo do-release-upgrade

Checking for a new Ubuntu release

Get:1 Upgrade tool signature [198 B]
Get:2 Upgrade tool [1,156 kB]
Fetched 1,156 kB in 0s (0 B/s)

authenticate 'trusty.tar.gz' against 'trusty.tar.gz.gpg' extracting 'trusty.tar.gz'

Also, while an LTS-to-LTS upgrade should preserve all your files it would be prudent to make a backup of any important documents, folders and photos before you begin. It’s rare for ‘direct upgrades’ to go wrong, but never say never.

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Upgrade Guide UBUNTU 12.04 To 14.04 Trusty

Backups

Make sure you have full backups of everything on your server that is important to you. At the very least, you should generate full backups of all your Virtual Servers. You may also want to make a backup of everything in /etc.

Package Updates

Make sure your system is fully up to date by running these commands:

sudo apt-get update
sudo apt-get upgrade

Reset Dependency Flags

These packages are already installed, but the following command will tell apt not include them anytime "apt-get autoremove" is run:

apt-get install bind9 spamassassin spamc procmail libnet-ssleay-perl libpg-perl libdbd-pg-perl libdbd-mysql-perl quota iptables openssl python mailman subversion ruby irb rdoc ri mysql-server mysql-client mysql-common postgresql postgresql-client awstats webalizer dovecot-common dovecot-imapd dovecot-pop3d proftpd webmin usermin webmin-virtual-server libcrypt-ssleay-perl webmin-virtual-server-theme webmin-virtualmin-dav webmin-virtualmin-svn webmin-virtualmin-awstats webmin-virtualmin-mailman webmin-virtualmin-htpasswd clamav-base clamav-daemon clamav clamav-data clamav-freshclam clamav-docs clamav-testfiles libapache2-mod-fcgid scponly apache2 apache2-doc libapache2-svn libsasl2-2 libsasl2-modules sasl2-bin usermin-virtual-server-theme procmail-wrapper php-pear php5 php5-cgi webmin-security-updates

Update Manager

Make sure you have the update manager core by running this command:

sudo apt-get install update-manager-core

Begin Upgrade

Run the following command to begin the upgrade process. Ubuntu suggests running this from the console, though it should also work from SSH:

do-release-upgrade -d

And then follow the on-screen instructions.

In general, if you are prompted about whether to replace a config file with a new one, or keep your existing one -- we would suggest keeping your existing config.

Coffee

Now is an excellent time to go get some coffee or another beverage of choice, while the packages are downloaded and installed :-)

Reboot

When the upgrade completes, it will prompt you to reboot your system. Perform the reboot, and when your system comes back online, there's just a few more things to change.

Change apt config

Edit /etc/apt/sources.list, and uncomment the Virtualmin repositories. Then change any references of "precise" in those repositories to "trusty".

Run this command, and make sure the new apt config works properly:

apt-get update

Apache Config

There were some significant changes made to Apache. You'll need to make the following updates to /etc/apache2/apache2.conf:

Comment out the following lines that appear in the apache2.conf:

Include httpd.conf
Include conf.d
LockFile ${APACHE_LOCK_DIR}/accept.lock

Re-enable Apache modules:

a2enmod suexec
a2enmod actions

Now enable some Apache modules:

a2enmod suexec
a2enmod rewrite

Then restart Apache:

service apache2 restart

Verify DNS Config

Edit /etc/resolv.conf, and verify that the nameserver line is configured to use 127.0.0.1 as a nameserver.

Test

That's it for configuring your updated system. Now it's time to test your services and websites!

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