If you ever set up a new domain hosting or migrate a domain to a new server, you will want to check to make sure that the changes are good before changing the DNS to the new server.

We often get asked this question a lot as in many cases, clients change the DNS before checking to see if there site actually works. This can lead to frustration, downtime and lost revenue and customers.

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Here are the different apps in linux for compressing and archiving files.


Tarball: A tarball is a collection of multiple files in Linux stored as a single file. The term tarball comes from the coal-based sealant used during construction works. A tarball is often simply called a TAR file, which stands for Tape Archive. This is because the TAR filetype was originally created to store data in magnetic tapes.

Gzip: GNU gzip is a file compression algorithm used to compress files. The file extension for gzip is GZ and therefore, you can deduce that any file ending with GZ has been compressed using the gzip algorithm.

TAR.GZ: A TAR.GZ file is a version of a tarball compressed with the gzip algorithm. TAR is the file extension for tarballs, whereas GZ denotes gzip. The TGZ file extension is also used sometimes instead of TAR.GZ.

Bzip2: Similar to gzip, several other file compression algorithms are also available, including bzip2. When you compress a TAR file using bzip2, the output file will have either of the following extensions: TAR.BZ2, TAR.BZ, or simply TBZ.

How to Create TAR and TAR.GZ Files

Using the tar Utility
The basic syntax to create compressed tarballs using the tar command is:

$ sudo tar -cvzf archive filename
$ sudo tar -cvzf archive directory

Note that you need to pass the file extension (TAR or TAR.GZ) in the archive name as follows:

$ sudo tar -cvzf new.tar.gz big-file.txt
$ sudo tar -cvf new.tar big-file.txt

To archive and compress the /Documents directory using tar:

$ sudo tar -cvzf new.tar.gz ~/Documents

You can also compress multiple directories and files by creating a single tarball. To do so:

$ sudo tar -cvzf new.tar.gz ~/Documents ~/Downloads file1.txt file2.txt

Install clamav

$ sudo apt-get install clamav clamav-daemon

Install this script to run a scan daily. Change the varables as needed.

LOGFILE="/var/log/clamav/clamav-$(date +'%Y-%m-%d').log";
EMAIL_MSG="Please see the log file attached.";
DIRTOSCAN="/var/www /etc /root /home";

for S in ${DIRTOSCAN}; do
 DIRSIZE=$(du -sh "$S" 2>/dev/null | cut -f1);

 echo "Starting a daily scan of "$S" directory.
 Amount of data to be scanned is "$DIRSIZE".";

 clamscan -ri "$S" >> "$LOGFILE";

 # get the value of "Infected lines"
 MALWARE=$(tail "$LOGFILE"|grep Infected|cut -d" " -f3);

 # if the value is not equal to zero, send an email with the log file attached
 if [ "$MALWARE" -ne "0" ];then
 # using heirloom-mailx below
 echo "$EMAIL_MSG"|mail -a "$LOGFILE" -s "Malware Found" -r "$EMAIL_FROM" "$EMAIL_TO";

exit 0

Set up the repository
Update the apt package index and install packages to allow apt to use a repository over HTTPS:

$ sudo apt-get update
$ sudo apt-get install ca-certificates curl gnupg lsb-release

Add Docker’s official GPG key:

$ curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Use the following command to set up the stable repository.

echo \
 "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/debian \
  $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Install Docker Engine

Update the apt package index, and install the latest version of Docker Engine and containerd, or go to the next step to install a specific version:

$ sudo apt-get update
$ sudo apt-get install docker-ce docker-ce-cli containerd.io

Verify that Docker Engine is installed correctly by running the hello-world image.

$ sudo docker run hello-world

Configure Docker to start on boot

$ sudo systemctl enable docker.service
$ sudo systemctl enable containerd.service

Manage Docker as a non-root user
Create the docker group.

sudo groupadd docker

Add your user to the docker group.

sudo usermod -aG docker $USER

Log out and log back in so that your group membership is re-evaluated. If testing on a virtual machine, it may be necessary to restart the virtual machine for changes to take effect. On a desktop Linux environment such as X Windows, log out of your session completely and then log back in.

On Linux, you can also run the following command to activate the changes to groups:

newgrp docker 

Verify that you can run docker commands without sudo.

$ docker run hello-world

This command downloads a test image and runs it in a container. When the container runs, it prints a message and exits.

Configuring remote access with systemd unit file

Use the command sudo systemctl edit docker.service to open an override file for docker.service in a text editor. Add or modify the following lines, substituting your own values.

ExecStart=/usr/bin/dockerd -H fd:// -H tcp://

Save the file. Reload the systemctl configuration.

 sudo systemctl daemon-reload

Restart Docker.

 sudo systemctl restart docker.service

Check to see whether the change was honored by reviewing the output of netstat to confirm dockerd is listening on the configured port.

$ sudo netstat -lntp | grep dockerd

Configuring remote access with daemon.json

Set the hosts array in the /etc/docker/daemon.json to connect to the UNIX socket and an IP address, as follows:

      "hosts": ["unix:///var/run/docker.sock", "tcp://"]

Restart Docker. Check to see whether the change was honored by reviewing the output of netstat to confirm dockerd is listening on the configured port.

 sudo netstat -lntp | grep dockerd


How to use wget to download iso’s directly to proxmox 6.2-14. Here is the location for the iso file. There is 1 ISO – a Debian ISO that I uploaded to the GUI. Login the proxmox host via ssh. Now find the location as follows:

cd /var/lib/vz/template/iso
# ls -la
total 357384
drwxr-xr-x 2 root root      4096 Nov  1 08:41 .
drwxr-xr-x 5 root root      4096 Oct 31 16:35 ..
-rw-r--r-- 1 root root 365953024 Nov  1 08:41 debian-10.6.0-amd64-netinst.iso

Download ubuntu 16.04. You can also specify a directory for the file to download to, as well as choose a name for the download. Use the -O (output) option and enter the directory and file name after the URL.

# wget https://releases.ubuntu.com/16.04/ubuntu-16.04.7-server-amd64.iso -O /var/lib/vz/template/iso/ubuntu-16.04.7-se         rver-amd64.iso
--2020-11-01 11:35:34--  https://releases.ubuntu.com/16.04/ubuntu-16.04.7-server-amd64.iso
Resolving releases.ubuntu.com (releases.ubuntu.com)... 2001:67c:1360:8001::33, 2001:67c:1360:8001::34, 2001:67c:1562::25, ...
Connecting to releases.ubuntu.com (releases.ubuntu.com)|2001:67c:1360:8001::33|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 922746880 (880M) [application/x-iso9660-image]
Saving to: ‘/var/lib/vz/template/iso/ubuntu-16.04.7-server-amd64.iso’
/var/lib/vz/template/iso/ubuntu-16.04.7 100%[==============================================================================>] 880.00M  19.2MB/s    in 91s

2020-11-01 11:37:06 (9.64 MB/s) - ‘/var/lib/vz/template/iso/ubuntu-16.04.7-server-amd64.iso’ saved [922746880/922746880]

After the upload, you can see the new ISO in the GUI at p1 > local (storage) > Content.

This install in on Ubuntu 18.04. There is an excellent article for CentOS at – https://www.tecmint.com/install-asterisk-on-centos-7/
Please review aslo:
– https://wiki.asterisk.org/wiki/display/AST/Installing+Asterisk+From+Source
– https://community.asterisk.org/
– https://www.sangoma.com/articles/how-to-install-asterisk-11-on-ubuntu-12-4-lts/
– http://asteriskdocs.org/en/3rd_Edition/asterisk-book-html-chunk/asterisk-Install.html

Install Requirements:

Firewalld. See the Article here to set up asterisk on firewalld – https://www.geekdecoder.com/firewalld-on-centos-8/-

The command installs a bunch of new packages including gcc, g++ and make

# apt install build-essential


Help Finding the Right Libraries

Asterisk comes with a shell script called install_prereq.sh in the contrib/scripts sub-directory. If you run install_prereq test, it will give you the exact commands to install the necessary system libraries on your operating system. If you run install_prereq install, it will attempt to download and install the prerequisites automatically.

cd /usr/local/src/asterisk-17.3.0/contrib/scripts/
./install_prereq test
./install_prereq install

The script calls for calling code (https://en.wikipedia.org/wiki/List_of_country_calling_codes)

Download Files:

Go to the following to see the current asterisk release:

Here is what I am using:

Asterisk – https://downloads.asterisk.org/pub/telephony/asterisk/asterisk-17-current.tar.gz
dahdi-complete – https://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/dahdi-linux-complete-current.tar.gz
dahdi-linux – https://downloads.asterisk.org/pub/telephony/dahdi-linux/dahdi-linux-current.tar.gz
dahdi-tools – https://downloads.asterisk.org/pub/telephony/dahdi-tools/dahdi-tools-current.tar.gz
libpri – https://downloads.asterisk.org/pub/telephony/libpri/libpri-current.tar.gz

Change directory:

# cd /usr/local/src

Get the files:

wget https://downloads.asterisk.org/pub/telephony/asterisk/asterisk-17-current.tar.gz
# wget https://downloads.asterisk.org/pub/telephony/dahdi-linux-complete/dahdi-linux-complete-current.tar.gz
# wget https://downloads.asterisk.org/pub/telephony/dahdi-linux/dahdi-linux-current.tar.gz
# wget https://downloads.asterisk.org/pub/telephony/dahdi-tools/dahdi-tools-current.tar.gz
# wget https://downloads.asterisk.org/pub/telephony/libpri/libpri-current.tar.gz

Lets extract

tar -zxvf asterisk-17-current.tar.gz
# tar -zxvf dahdi-linux-complete-current.tar.gz
# tar -zxvf dahdi-linux-current.tar.gz
# tar -zxvf dahdi-tools-current.tar.gz
# tar -zxvf libpri-current.tar.gz

You should now notice that a new sub-directory was created for each of the tarballs, each containing the extracted files from the corresponding tarball. We can now compile and install each of the components.

Building and Installing DAHDI
Let’s install DAHDI!
On Linux, we will use the DAHDI-linux-complete tarball, which contains the DAHDI Linux drivers, DAHDI tools, and board firmware files.

# cd dahdi-linux-complete-3.1.0+3.1.0/
# make
# make install
# make config

Next, building and Installing LibPRI
Have you installed DAHDI? – Before you can build libpri, you’ll need to Build and Install DAHDI.

# cd libpri-1.6.0/
# make
# make install

Using Menuselect to Select Asterisk Options

The next step in the build process is to tell Asterisk which modules to compile and install, as well as set various compiler options. These settings are all controlled via a menu-driven system called Menuselect. To access the Menuselect system, type:

# make menuselect

When you’re first learning your way around Asterisk on a test system, you’ll probably want to stick with the default settings in Menuselect. If you’re building a production system, however, you may not wish to build all of the various modules, and instead only build the modules that your system is using. When you are finished selecting the modules and options you’d like in Menuselect, press F12 to save and exit, or highlight the Save and Exit button and press enter.

See More here: https://wiki.asterisk.org/wiki/display/AST/Using+Menuselect+to+Select+Asterisk+Options

Install asterisk with pre-bundled PJSIP-pjproject

# cd /usr/local/src/asterisk-17.3.0
# ./configure
# make && make install

You should see:

 +---- Asterisk Installation Complete -------+
 +                                           +
 +                                           +
 + Asterisk has successfully been installed. +
 + If you would like to install the sample   +
 + configuration files (overwriting any      +
 + existing config files), run:              +
 +                                           +
 + For generic reference documentation:      +
 +    make samples                           +
 +                                           +
 + For a sample basic PBX:                   +
 +    make basic-pbx                         +
 +                                           +
 +                                           +
 +-----------------  or ---------------------+
 +                                           +
 + You can go ahead and install the asterisk +
 + program documentation now or later run:   +
 +                                           +
 +               make progdocs               +
 +                                           +
 + **Note** This requires that you have      +
 + doxygen installed on your local system    +

Installing Sample Files

Asterisk Sample Configs: not a sample PBX configuration

For many of the sample configuration files that make samples installs, the configuration contains more than just an example configuration. The sample configuration files historically were used predominately for documentation of available options. As such, they contain many examples of configuring Asterisk that may not be ideal for standard deployments.

While installing the sample configuration files may be a good starting point for some people, they should not be viewed as recommended configuration for an Asterisk system.

To install a set of sample configuration files for Asterisk, type:

# make samples

Any existing sample files which have been modified will be given a .old file extension. For example, if you had an existing file named extensions.conf, it would be renamed to extensions.conf.old and the sample dialplan would be installed as extensions.conf.

Installing Initialization Scripts

Now that you have Asterisk compiled and installed, the last step is to install the initialization script, or initscript. This script starts Asterisk when your server starts, will monitor the Asterisk process in case anything bad happens to it, and can be used to stop or restart Asterisk as well. To install the initscript, use the make config command.

# make config

As your Asterisk system runs, it will generate logfiles. It is recommended to install the logrotation script in order to compress and rotate those files, to save disk space and to make searching them or cataloguing them easier. To do this, use the make install-logrotate command.

# make install-logrotate

Validating Your Installation

Before continuing on, let’s check a few things to make sure your system is in good working order. First, let’s make sure the DAHDI drivers are loaded. You can use the lsmod under Linux to list all of the loaded kernel modules, and the grep command to filter the input and only show the modules that have dahdi in their name.

# lsmod | grep dahdi

If the command returns nothing, then DAHDI has not been started. Start DAHDI by running:

# /etc/init.d/dadhi start

Asterisk can now be started as a service:

# service asterisk start
 * Starting Asterisk PBX: asterisk                                                                               [ OK ] 

And stopped:

# service asterisk stop
 * Stopping Asterisk PBX: asterisk                                                                               [ OK ] 

And restarted:

# service asterisk restart
 * Stopping Asterisk PBX: asterisk                                                                               [ OK ] 
 * Starting Asterisk PBX: asterisk                                                                               [ OK ]

Asterisk Console

# asterisk -rvvvvv

Let set up a SIP client and Make a test call. Configure extensions.conf. Backup the sample extensions.conf and create a new one

# mv extensions.conf extensions.sample
# vim extensions.conf

We are going to use a very simple dialplan. A dialplan is simply instructions telling Asterisk what to do with a call. Edit your blank extensions.conf to reflect the following:

exten = 100,1,Answer()
same = n,Wait(1)
same = n,Playback(hello-world)
same = n,Hangup()
When a phone dials extension 100, we are telling Asterisk to Answer the call, Wait one second, then Play (Playback) a sound file (hello-world) to the channel and Hangup.

Configure a SIP channel driver. Depending on the version of Asterisk in use, you may have the option of more than one SIP channel driver. You'll have to pick one to use for the example.
Asterisk 11 and previous: chan_sip is the primary option. Asterisk 12 and beyond: You'll probably want to use chan_pjsip (the newest driver), but you still have the option of using chan_sip as well
Follow the instructions below for the channel driver you chose. Configure chan_sip Backup and edit a new blank sip.conf. Then add the following to your sip.conf file:


Configure chan_pjsip

Backup and edit a new blank pjsip.conf. Then add the following to your pjsip.conf file:





Configure your SIP phone

Use Jitsi.

Once Jitsi is opened, click Tools > Options > Add.
Select the "SIP" Network".
For "SIP id", Enter 6001.
Enter your SIP peer's password(see above - unsecurepassword) in the Password field.
Click Advanced. Add your Display Name. Click the Connection Tab.
Put in the IP for the asterisk server in the "Registrar" Field.
Review and Click Sign in.

You should see the registration in asterisk:

Start Asterisk. Back at the Linux shell go ahead and start Asterisk. We'll start Asterisk with a control console (-c) and level 5 verbosity (vvvvv).

# asterisk -cvvvvv

Or if Asterisk is already running, restart Asterisk from the shell and connect to it.

# asterisk -rx "core restart now"
# asterisk -rvvvvv

Make the call. Once registered, enter extension 100 and click the Dial button. The call should be made and you should hear the sound file hello-world!

On the Asterisk CLI, you should see something like: