How to Install GTK-RecordMyDesktop on RHEL 7 (best screen recording software imo)

If you want to record your screen to make tutorials or something else, GTK-recordmydesktop is capable of doing it. Most of the screen-recording programs that I have come across requires you to record your audio separately, however this software is also capable of recording audio without any extra step. It can also work with JACK audio server.

PART 1 - Install EPL repository for RHEL 7:

1. Open a terminal
2. Install epel using the following command: yum -y install epel-release.
3. Refresh repo by typing the following commad: yum repolist.

PART 2 - Install GTK-RecordMyDesktop:

1. yum install gtk-recordmydesktop

That's it, it should work right away. If it doesn't, it is possible that you might be missing some codecs as I installed them from nux and epel repos earlier.

How to Install Nvidia Drivers on Redhat/Centos 7 - Step by Step guide

1. Nvidia needs "Development Tools" installed, if you installed it during RHEL installation, you're good, if you didn't, then execute the following commands:

[root@localhost rpmbuild]# yum groups mark install "Development Tools" [root@localhost rpmbuild]# yum groups mark convert "Development Tools"
[root@localhost rpmbuild]# yum groupinstall "Development Tools"

 
2. Install Kernel Devel and Kernel headers
   

        yum install kernel-devel kernel-headers dkms

3. Now run the following to get to know your Graphics Card (if you already know you can skip this part)

   lspci -nn | grep VGA

4. Now download the appropriate driver from NVIDIA Downloads
5. Open “/etc/modprobe.d/blacklist.conf” and add "blacklist nouveau" to the file (if it doesn't exist then create it)
6. Create a new initramfs and take a backup of the existing one (this might not be needed as i think NVIDIA installer already does this, do it regardless)
   

   mv /boot/initramfs-$(uname -r).img /boot/initramfs-$(uname -r).img.bak  
   dracut -v /boot/initramfs-$(uname -r).img $(uname -r)

7. Reboot your computer and login again
8. Open a terminal and type:
   

   init 3

9. Login as root, navigate to the folder where you have downloaded NVIDIA installer file and do the following:
   

   chmod 755 (NVIDIA installer filename)
   ./(NVIDIA Installer Filename)

10. Go through the NVIDIA installer prompts, you can choose to install 32 bit libraries, but do save the X configurations at the end.

Cheers!
Source:
This is a compilation of various articles
http://www.tecmint.com/install-nvidia-drivers-in-linux/
https://access.redhat.com/discussions/1262603

How to Install Spotify on Debain GNU/Linux 8 (Jessie)

These instructions are from Spotify's Website:

# 1. Add the Spotify repository signing key to be able to verify downloaded packages
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys BBEBDCB318AD50EC6865090613B00F1FD2C19886

# 2. Add the Spotify repository
echo deb http://repository.spotify.com stable non-free | sudo tee /etc/apt/sources.list.d/spotify.list

# 3. Update list of available packages
sudo apt-get update

# 4. Install Spotify
sudo apt-get install spotify-client

I can confirm that they work exactly as written on Debian Jessie, I know some things aren't required for Debain(sudo),

it's a bigger hassle to remove them instead of just copy/pasting :)

Enjoy!

Source:

https://www.spotify.com/ca-en/download/linux/

Replace VI with VIM on Debian 7

Make sure you can access internet before attempting this.

• Open the terminal
• apt-get install vim
• sudo vi /etc/vim/vimrc

Uncomment the "syntax on" line to enable color coding that vim comes with. This will replace vi with vim, if you edit a file with say "vi .bashrc" it should show you color coded text instead of just black and white.

Configuring and Deploying DNS servers (primary, secondary, root and cache on centos 6.5) - Part 3 - Root and Cache

Configuration on Root DNS Server:

The root zone maintains information regarding top-level domains. Root-zone servers for internet top-level domains are already deployed. With this you can create your own internet naming scheme, which is usually done in intranets who have their own top-level domains

• Install bind packages
• yum install bind bind-utils bind-chroot bind-libs

• Edit named.conf
• vi /etc/named.conf

listen-on port 53 { 192.168.12.4; }; //change this to your ip address
*remove the allow-query line
*optional remove recursion line

 zone "." IN {
        type master;
        file "root.net";
      };

• Create and edit root.net
• vi /var/named/root.net

 $TTL 86400
@    IN    SOA    root.msm.net.    admin.root.msm.net. (
            535 ; serial
            3H ; refresh
            15M ; retry
            1W ; expiry
            1D ) ; minimum
@                IN    NS    root.msm.net.
root.msm.net.    999999        IN    A    192.168.12.4 //root servers ip and fqdn
msm.net.            IN    NS    ns.msm.net. //primary server's fqdn and zone name
12.168.192.in-addr.arpa        IN    NS     ns.msm.net. // reverse zone named and fqdn of primary dns server
ns.msm.net.            IN    A    192.168.12.2 //fqdn and ip of primary dns server, you can also add similar entries for secondary dns below

• Open Firwalls
• iptables -I INPUT -p tcp --dport 53 -j ACCEPT
• iptables -I INPUT -p udp --dport 53 -j ACCEPT 

•  edit resolv.conf
• vi /etc/resolv.conf

search msm.net
nameserver 192.168.12.4 //resolve to its own ip address just to check if server is functioning

• Start named daemon
• service named start

• Query some records that are stored in primary server's database
• nslookup
• cache.msm.net 

 Configuration on Cache DNS server:

when DNS(bind named) is installed, by default it configures the machine as a caching server. All we have to do is change the file-name in named.conf and create a file accordingly to point towards our own root DNS server.

• Install bind packages
• yum install bind bind-utils bind-chroot bind-libs 

•  Edit named.conf
• vi /etc/named.conf

listen-on port 53 { 192.168.12.5; }; //change this to your ip address
*Remove the allow-query line
*Remove dnssec-lookaside auto;
*DON'T remove the recursion line. Of all the servers, this is the only one that must do recursion

 zone "." IN {
        type hint;
        file "file.ca";
      };

*Remove include "/etc/named.root.key";

• Create and edit file.ca
• vi /var/named/file.ca

  .        999999    IN    NS    root.msm.net. \\fqdn of root dns server
root.msm.net.    999999        A    192.168.12.4 \\fqdn and ip address of root dns server

• Open Firwalls
• iptables -I INPUT -p tcp --dport 53 -j ACCEPT
• iptables -I INPUT -p udp --dport 53 -j ACCEPT 

•  edit resolv.conf
• vi /etc/resolv.conf

search msm.net
nameserver 192.168.12.5 //resolve to its own ip address

• Start named daemon
• service named start

• Query some records that are stored in primary server's database
• nslookup
• cache.msm.net

 If this is successful then change the /etc/resolv.conf in all the DNS servers to point to caching server IP address to reduce the load on Primary/Secondary and distribute it towards cache.

Prefer a Video Walkthrough?

Check this wiki page for more information on what's being done
http://en.wikipedia.org/wiki/Alternative_DNS_root

 That's all folks.
 Enjoy.

How to install Avidemux on Centos6

• Create and edit /etc/yum.repos.d/naulinux-school.repo

add these lines

[naulinux-school]
name=NauLinux School
baseurl=http://downloads.naulinux.ru/pub/NauLinux/6.2/$basearch/sites/School/RPMS/
enabled=0
gpgcheck=1
gpgkey=http://downloads.naulinux.ru/pub/NauLinux/RPM-GPG-KEY-linux-ink

• Run this command and it will install it
• yum --enablerepo=naulinux-school install avidemux

ENJOY! 


SOURCE:
https://www.centos.org/forums/viewtopic.php?f=13&t=2491&sid=53e0d3877a6af3ea5f267d2754098cbf&start=10

Configuring and Deploying DNS servers (primary, secondary, root and cache on centos 6.5) - Part 2 - Secondary DNS

This walk-through assumes that you have initial deployment of Primary DNS server. Look at my previous post for that.

Configuration on Primary DNS server:

• edit /etc/named.conf

add the allow transfer statement in your zone declaration(both forward and reverse)

 zone "msm.net" {
        type master;
        file "msm.net.db";
        allow-transfer { 192.168.12.3; };
};

zone "12.168.192.in-addr.arpa" {
        type master;
        file "msm.net.rev.db";
        allow-transfer { 192.168.12.3; };
};

•  Allow firewall to communicate on tcp/udp port 53
• iptables -I INPUT -p tcp --dport 53 -j ACCEPT
• iptables -I INPUT -p udp --dport 53 -j ACCEPT

• Restart the named deamon
• service named restart

Configuration on Secondary DNS server:

Make sure you have internet access.

• Install Bind packages
• yum install bind bind-utils bind-chroot bind-libs

• edit /etc/named.conf

 listen-on port 53 { 192.168.12.3; }; //Ip address of the machine
*Remove the allow-query line
*Optional: remove recursion statement and the "." zone to disable recursion and caching.

 zone "msm.net" { //your forward zone statement, same as primary
        type slave; //slave sets this server as slave
        file "msm.net.db"; //the file name that you created in primary
        masters { 192.168.12.2; }; //this is telling the server that this ip is my primary dns's ip
        allow-transfer { none; };
};

zone "12.168.192.in-addr.arpa" { //reverse lookup zone statement, same as primary
        type slave; //this sets this server as a slave of this reverse zone
        file "msm.net.rev.db";  //the file name that you created in primary for reverse  zone
        masters { 192.168.12.2; }; //primary server's ip address
        allow-transfer { none; };
};

• Add exception in SELINUX
•  setsebool -P named_write_master_zones 1

• make name the owner of /var/named directory
• chown named:named /var/named

• Start the named daemon
• service named start

• Check logs if everything went well. It should say zone loaded and file transfered
• tail -30 /var/log/messages

 named[21296]: transfer of 'msm.net/IN' from 192.168.12.2#53: Transfer completed: 1 messages, 7 records, 206 bytes, 0.001 secs (206000 bytes/sec)


If everything went fine then you should see your zone files under /var/named automatically transferred by starting the named daemon, this transfer of file is called a zone transfer.

Prefer a video walk-through? have a look...