Introduction to NAS

Network Attached Storage (NAS) is a file-level data storage technology that provides a central location for storing and managing digital files. It connects to your local area network (LAN) and can be accessed by multiple devices over the network. NAS devices are typically equipped with one or more hard drives and offer a range of features such as data backup, media streaming, and remote access.

II. Types of NAS

There are various types of NAS available in the market, each with its own set of features and capabilities. Here are some of the key types of NAS:

1. Consumer NAS vs Enterprise NAS

• Consumer NAS devices are designed for home users and small businesses. They are typically cheaper and have fewer features compared to enterprise-grade NAS devices.
• Enterprise-grade NAS devices are designed for large businesses and offer advanced features such as data deduplication, tiered storage, and virtualization.

1. Rackmount vs Desktop NAS

• Rackmount NAS devices are designed to be mounted on a server rack and are typically used by businesses with large storage requirements.
• Desktop NAS devices are smaller in size and can be placed on a desk or shelf. They are suitable for home users and small businesses.

1. HDD vs SSD NAS

• HDD-based NAS devices are equipped with hard disk drives and offer high storage capacity at a lower cost.
• SSD-based NAS devices are equipped with solid-state drives and offer faster data transfer speeds and better reliability than HDD-based NAS devices.

1. Single-bay vs Multi-bay NAS

• Single-bay NAS devices are equipped with one hard drive bay and are suitable for home users with basic storage needs.
• Multi-bay NAS devices are equipped with two or more hard drive bays and offer higher storage capacity and redundancy.

Security considerations for NAS

NAS devices store valuable data and therefore, it’s important to take security considerations seriously. Here are some best practices for securing your NAS:

1. Change the default login credentials – The default login credentials for NAS devices are usually easy to guess, so it’s important to change them to something more secure.
2. Enable two-factor authentication – Two-factor authentication adds an extra layer of security to your NAS device by requiring a second form of authentication, such as a code sent to your phone, in addition to your password.
3. Keep your NAS software up-to-date – Regularly updating your NAS software can help to fix any security vulnerabilities that may exist.
4. Enable data encryption – Data encryption can protect your data in case of unauthorized access or theft.
5. Use a strong password – Use a strong password that is unique and difficult to guess. Avoid using common words or phrases, and consider using a password manager to generate and store your passwords.
6. Disable unnecessary services – Only enable the services that you need to use on your NAS device. Disabling unnecessary services can help to reduce the risk of a security breach.
7. Regularly back up your data – Regularly backing up your data is a critical step in protecting against data loss in case of a security breach.

Setting up NAS

Setting up NAS is a relatively simple process, but it requires a few steps to ensure that it’s done correctly. Here are some steps to follow when setting up NAS:

1. Requirements for setting up NAS – You’ll need a few things to set up NAS, including a NAS device, a hard drive (or multiple hard drives), a network cable, and a computer.
2. Choosing the right NAS for your needs – There are many different types of NAS devices available, so it’s important to choose one that meets your specific needs. Consider factors such as the number of hard drive bays, storage capacity, and the features that you require.
3. Configuring NAS – Once you have your NAS device, you’ll need to configure it. This involves connecting the NAS device to your network, installing the necessary software, and setting up user accounts and access permissions.
4. Creating shared folders – Once your NAS device is configured, you can create shared folders that can be accessed by other devices on your network. This is a great way to share files and media with other users.
5. Setting up data backup – Data backup is an important part of NAS, and most NAS devices have built-in backup features. You can set up automated backups to protect your data in case of a hardware failure or other disaster.
6. Enabling remote access – Many NAS devices offer remote access, which allows you to access your files from anywhere with an internet connection. This is a convenient feature for people who need to access their files on-the-go.

By following these steps, you can set up NAS and start enjoying the benefits of network-attached storage.

To generate a CSR (Certificate Signing Request) code for an SSL certificate, you can follow these general steps:

1. Log in to the web hosting control panel or server where you want to install the SSL certificate.
2. Find the option to generate a new SSL certificate or CSR. This will typically be in the Security or SSL section of the control panel.
3. Fill in the required information for the certificate, including the domain name, organization name, country, and contact details.
4. Choose the key size and algorithm for the CSR. A common option is 2048-bit RSA.
5. Generate the CSR code and save it to a file. The CSR will typically include a block of text starting with “—–BEGIN CERTIFICATE REQUEST—–” and ending with “—–END CERTIFICATE REQUEST—–“.
6. Submit the CSR code to a trusted SSL certificate authority (CA) to purchase and obtain the SSL certificate. The CA will use the information in the CSR to verify your domain and organization details and generate the certificate.

Note that the exact steps and options for generating a CSR code may vary depending on your web hosting or server setup. It is also important to keep the private key associated with the CSR secure and protected, as it is used to encrypt and decrypt communications for the SSL certificate.

One of the greatest open-source monitoring tools is Nagios, which keeps an eye on services and programs running on Linux and Windows operating systems.

Nagios can keep an eye on system metrics including CPU load, memory consumption, disk utilization, logged-in users, active processes, and services like HTTP, FTP, SSH, and SMTP.

We’ll look at how to set up Nagios on Ubuntu 22.04 in this article.

Prerequisites:
We shall compile Nagios from source even though there is a package for it in the Ubuntu repository. Therefore, install the packages listed below to compile Nagios.

#sudo apt update

#sudo apt install -y build-essential apache2 php openssl perl make php-gd libgd-dev libapache2-mod-php libperl-dev libssl-dev daemon wget apache2-utils unzip

For Nagios, create a user and group. Then, to enable external commands to be executed via the Nagios web interface, add the nagios and apache user (www-data) to the section of the nagcmd group.

#sudo useradd nagios

#sudo groupadd nagcmd

#sudo usermod -a -G nagcmd nagios

#sudo usermod -a -G nagcmd www-data

Nagios Core installation for Ubuntu 22.04
First, get the most recent Nagios core version from the official website.

#wget https://assets.nagios.com/downloads/nagioscore/releases/nagios-4.4.6.tar.gz

#tar -zxvf nagios-4.4.6.tar.gz

#cd nagios-4.4.6/

Then, use the procedures listed below to build Nagios from source code.

#sudo ./configure --with-nagios-group=nagios --with-command-group=nagcmd --with-httpd_conf=/etc/apache2/sites-enabled/

#sudo make all

#sudo make install

#sudo make install-init

#sudo make install-config

#sudo make install-commandmode

You can find Nagios’s configuration files under the /usr/local/nagios/etc directory, and the default configuration should work fine.

Next, install the Nagios web interface with the below command.

#sudo make install-webconf

You must establish a user account (nagiosadmin) in order to access the Nagios web interface, which is password secured by default. So, to establish a user account for the Nagios online interface, execute the command below.

#sudo htpasswd -c /usr/local/nagios/etc/htpasswd.users nagiosadmin

Enable the CGI module using the following command.

#sudo a2enmod cgi

Restart the Apache web server to finish.

Adding plugins to Nagios with Ubuntu 22.04
Installing Nagios plugins is required in order to monitor a system. Install the Nagios plugins by downloading them from the official website.

#wget https://nagios-plugins.org/download/nagios-plugins-2.3.3.tar.gz
#tar -zxvf nagios-plugins-2.3.3.tar.gz
#cd nagios-plugins-2.3.3/

Then, compile and install the Nagios plugins.

#sudo ./configure --with-nagios-user=nagios --with-nagios-group=nagios

#sudo make

#sudo make install

Open the Nagios monitoring program
It's time to launch the Nagios service at this point. You should check the Nagios configuration files before launching the service.

#sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

Output:
Nagios Core 4.4.6
right (c) 2009-present Nagios Core Development Team and Community Contributors
Copyright (c) 1999-2009 Ethan Galstad
Last Modified: 2020-04-28
License: GPL
Website: https://www.nagios.org
Reading configuration data...
Read main config file okay...
Read object config files okay...
Running pre-flight check on configuration data...
Checking objects...
Checked 8 services.
Checked 1 hosts.
Checked 1 host groups.
Checked 0 service groups.
Checked 1 contacts.
Checked 1 contact groups.
Checked 24 commands.
Checked 5 time periods.
Checked 0 host escalations.
Checked 0 service escalations.
Checking for circular paths...
Checked 1 hosts
Checked 0 service dependencies
Checked 0 host dependencies
Checked 5 timeperiods
Checking global event handlers...
Checking obsessive compulsive processor commands...
Checking misc settings...
Total Warnings: 0
Total Errors: 0
Things look okay - No serious problems were detected during the pre-flight check

Then, start and enable the Nagios service with the below command

#sudo systemctl enable --now nagios

Now navigate to the following URL in your web browser to view the Nagios web interface.
Enter the login (nagiosadmin) and password for the Nagios account you previously created at

http://ip/nagios/

You will see Nagios’ main page after successfully logging in.

To view the services that Nagios is watching, click Services in the left pane.

Now use the following command to install NRPE Add-on and Nagios plugins for adding Host.

#sudo apt update
#sudo apt install -y nagios-nrpe-server nagios-pluginss.

Set up NRPE Add-on
To accept the connection from the Nagios server, modify the NRPE configuration file, Change the file /etc/nagios/nrpe.cfg.

#sudo nano /etc/nagios/nrpe.cfg

Add the Nagios servers IP address, separated by comma like below.

#allowed_hosts=192.168.9.4


With the use of Nagios plugins, the command lines below allow you to keep an eye on the number of active processes, the number of logged-in users, the system load, root filesystem utilization, and swap consumption.

#sudo nano /etc/nagios/nrpe.cfg

Firewall
Set up the firewall so that the NRPE server operating on a distant Linux computer may be contacted by the Nagios server. Use a remote Linux computer to execute these instructions.

#firewall-cmd –permanent –add-port=5666/tcp
#firewall-cmd –reload

IP Tables

#iptables -I INPUT -p tcp –dport 5666 -m conntrack –ctstate NEW,ESTABLISHED -j ACCEPT
#iptables -I OUTPUT -p tcp –sport 5666 -m conntrack –ctstate ESTABLISHED -j ACCEPT
#/etc/init.d/iptables save

Install the NRPE plugin on the Nagios server.
To verify the services or resources, this NRPE plugin offers the check nrpe plugin, which makes communication with the NRPE server on distant computers.

Use the following command to install the NRPE plugin on your machine.

#sudo apt install -y nagios-nrpe-plugin

Configuration Editing
To add all.cfg files located in the /usr/local/nagios/etc/servers directory, edit the Nagios configuration file.

#sudo nano /usr/local/nagios/etc/nagios.cfg

Add or uncomment the following line.

cfg_dir=/usr/local/nagios/etc/servers

Create a configuration directory.

#sudo mkdir /usr/local/nagios/etc/servers

To the Nagios server, add a Linux host
To define the host and service definitions of a remote Linux host, create a client configuration file at /usr/local/nagios/etc/servers/client.itzgeek.local.cfg in your system.

#sudo nano /usr/local/nagios/etc/servers/client.itsupportbd.local.cfg

Add the following text to the file mentioned above.

The template below can also be used, and it can be customized to meet your needs. For monitoring logged-in users, system load, disk utilization (/ – partition), swap, and overall process, use the template below.

define host{
                           
            use                     linux-server            
            host_name               client.itsupportbd.local            
            alias                   client.itsupportbd.local            
            address                 192.168.9.10
                                    
}

Restart the Nagios server.

#sudo systemctl restart nagios


That is it. Please provide feedback in the section below.