Why?

Nagios is designed to monitor servers and services.

Under this service, you can understand a lot of things, such as http, ie, Web server running on some host.

The program is for everyone who is having a website and who wants to know, whether it is in working in good condition or not.

In this article I’ll show you the basic foundation for better understanding

Installation

First of all, you should set up apache / php web server .

Once the server is installed, put nagios:

Or via the console:

sudo apt-get install nagios3

During installation, you will be asked questions about the mail. Leave it to your discretion.

Start, stop nagios can be in the same way as the other modules:

sudo / etc/init.d/nagios3 start

sudo / etc/init.d/nagios3 stop

Let’s create a password for default user nagiosadmin:

sudo htpasswd-c / etc/nagios3/htpasswd.users nagiosadmin

Now open a browser and type in the address bar:

http://localhost/nagios3/

Instead of localhost substitute the desired value, if you install nagios on remote server.

Enter your username and password nagiosadmin specified above.

You should see the following picture:

On the left you will see a menu where you can select the desired item, and right – the actual result.

Choosing the left “Host Detail”.

You will see a list of hosts and their status. In my case, two of them: the machine is running on nagios, and a router.

Next, open the “Service Detail”.

On each host, it has its own set of “services”, which checks the nagios.

You will set default set’s of services for the local machine and installed nagios.

If you have a problem with Disk Space, as in my screenshot, I show below how to fix it.

Customize

As an example, I add the configuration for the site www.website.com.

I need to add a host and a couple of services.

Where are the main configuration files located?

In the directory / etc/apache2/conf.d / nagios3.conf file is located, from which it takes the Apache configuration for nagios.

nagios files are located in the directory / etc/nagios3.

File / etc/nagios3/htpasswd.users contains passwords for the nagios user. Command to create the file and set the password for default user nagios is quoted above. In the future, you will need to omit the argument “-c” if you set a password for the user, otherwise a new file will overwrite the old one.

File / etc/nagios3/nagios.cfg contains the basic configuration of the nagios. For example, logs, or the path to the other configuration files that nagios reads at startup.

The most interesting is in the directory / etc / nagios / conf.d.

Go to the directory and view the contents of files to keep in mind a rough picture of what is happening. Hosts are specified through a directive define host, through the services directive to define service. There is a group of hosts, which we will now use.

Create a new file:

sudo gedit / etc/nagios3/conf.d/host-website.cfg

Rather than host-website.cfg write the name of your host that you want.

You can copy the definition of a host of file localhost_nagios2.cfg. Here’s what happened with me:

define host {
host_name website
alias website
address website.com
use generic-host
}

In the address write address of the host. It could be either the site address or ip-address.

In the host_name write identifier, which will use more.

In the following alias write anything.

At the moment, leave the field to use generic-host, and in the future you decide what to write there, after further reading the documentation.

Save the file and restart nagios.

Go to the “Host Details” page:

If you did everything correctly, you should see your new host in this list. Do not worry if the status is “Pending” – this means that nagios did not check out the new host yet.

The system does not check the nagios regularly but after a specifictime interval. After a while you’ll see results.

Now, to add services, we add our host in a group.

sudo gedit / etc/nagios3/conf.d/hostgroups_nagios2.cfg

You will see a list of host group.

All you need do is add your new hosts to a specific group.

In my case I added the host in three groups: debian-servers, http-servers and ping-servers

# A list of your Debian GNU / Linux servers
define hostgroup {
hostgroup_name debian-servers
alias Debian GNU / Linux Servers
Members localhost, website
}

# A list of your web servers
define hostgroup {
hostgroup_name http-servers
alias HTTP servers
Members localhost, website
}

# Nagios doesn’t like monitoring hosts without services, so this is
# A group for devices that have no other “services” monitorable
# (Like routers w / out snmp for example)
define hostgroup {
hostgroup_name ping-servers
alias Pingable servers
Members Gateway, website
}

Says the commentary to ping-servers, nagios does not like to monitor the dedicated hosting server without service, so a group of ping-servers can be used for all hosts that have no service. All that will nagios do is ping the server. I added it here just for illustration.

Group services http-servers is designed to check the availability of http.

A group of debian-servers are also taken as an example that you see below.

So restart nagios and open “Service Details”.

If you did everything correctly, you should see your new projects. In my case it’s http and ping. You may ask why it was adding a host to a group of debian-servers? Notice the icon next to the host. This is what is governed by this group. Setting up a group is in the file / etc/nagios3/conf.d/extinfo_nagios2.cfg.

That’s it. This concludes an overview of the nagios test. I hope that this article will help you to explore this beautiful tool and customize it to suit your needs. Also, nagios can even measure the CPU temperature and speed of cooler.

And finally, fix the problem with the disk space in Ubuntu:

sudo gedit / etc / nagios-plugins / config / disk.cfg

You need to add that is highlighted in bold:

# ‘Check_disk’ command definition
define command {
command_name check_disk
command_line / usr / lib / nagios / plugins / check_disk-w ‘$ ARG1 $’-C ‘$ ARG2 $’-p ‘$ arg3 $’ -A-I ‘. gvfs‘
}

# ‘Check_all_disks’ command definition
define command {
command_name check_all_disks
command_line / usr / lib / nagios / plugins / check_disk-w ‘$ ARG1 $’-C ‘$ ARG2 $’ -A-I ‘. gvfs’
}

As always when there’s something new in the market it is the most talked about topic. Similarly, with the launch of Peer to Peer there was a buzz around. When things come into existence its obvious that people start comparing with the products available in the industry. Peer to Peer (P2P) is a distributed application architecture which has multiple servers connected to each other, which can be said as computing or networking that has partitions tasks or work loads between peers. Peers are equally privileged, equipotent participants in the application. They are said to form a peer-to-peer network of nodes.

On the other hand dedicated servers act as the individual identity and one of the best opted solutions for the businesses. As we all know that dedicated server hosting is the most advantageous and robust technology which provides many a benefits to the users. Dedicated servers have own set of parameters and not being shared on any platform by any other user, all the resources are meant to be used by the single user itself. Whereas, Peers make a portion of their resources, such as processing power, disk storage or network bandwidth, directly available to other network participants, without the need for central coordination by servers or stable hosts. Peers are both suppliers and consumers of resources, in contrast to the traditional client–server model where only servers supply, and clients consume.

Dedicated Web Hosting Solution is basically considered by the large business groups who has the requirement of larger bandwidth, huge amount of space and has so many different requirements. Very small businesses, those with less than a handful of PCs, often use informal peer-to-peer networks to share files and printers. In sharp contrast to a more robust client/server network with a dedicated server computer, a peer-to-peer network is often selected to keep costs to a minimum and is generally built around a consumer-oriented operating system, such as Microsoft Windows 98.

There can be so many advantages and pitfalls too of investing in both the servers. It depends on the requirement and the particular choice of the people what exactly they are looking for. If we discuss about the Gaming server part then surely we a handful of information to distinguish them like in dedicated server Nobody is the host. There is minimal ping difference, as people always tend to join servers closest to them, therefore the lag, in 99% of cases. When we speak about peer to peer server as the name implies, is a way of having an online game with no servers involved apart from a master server (like IWNet, the server for MW2 on PC, PS3 and 360). Basically, it looks for the person with the best connection. The best upload speed will be the best host. Generally, Dedicated Servers are paid for by the community, not the game developers. All the game developers need to do is have a master server, like any other, to hold the list of all the servers people have bought and maintained with their own money. On the Peer to Peer side P2P is choice free, and completely controlled. P2P has playlists. This means you just choose to play a game type like CTF or Domination or Team Slayer / Team Deathmatch.

From the above discussion its more over clear that which is a better option to opt for. This gives a fair view about the Dedicated web servers as well as the Peer to Peer servers.

When you look at any technical aspect of the server it is considered that it may come up with an technical issues. Similarly, active directory issues on dedicated servers is one of them. The technical aspect can face some or the other issues because it is automated not man made. Active Directory sites are a very important topic and yet are commonly misconfigured. A site is a combination of the physical (wires, cables, routers, etc.) and the logical (Active Directory configuration, IP Subnet, etc.). A site may span one or more domains. A site needs to be able to allow all the domain controllers within it to replicate to each other in a timely fashion. Clients will treat all DCs in the site as equals.

There are different active directories issues that may occur like Dynamic DNS Update Problems, Mail delivery Problems, Internet Protocol (IP) configuration, Active network connection during installation, Client connections and High-Encryption Pack and Internet connection software. Some of these are explained below:

IP Configuration : The issues with IP Configuration can be said as the one of the very common or basic issues in which if one doesn’t uses a dedicated IP then the DNS registration may not work So, one needs a dedicated IP address to install, the Active Directory domain controller should point to its own IP address in the DNS server list to prevent possible DNS connectivity issues, and Active Directory functionality shouldn’t be lost.

Active Network Connection Required During Installation : the heading itself explains that while installation is on there must be active network connection required. Active Directory Installation Failed’ Error Message When You Use Dcpromo.exe to Promote a Server

DNS Configuration : The DNS configuration plays an important role in installing active directory issues it (DNS) supports Active Directory DNS entries (SRV records) must be present for Active Directory to function properly. You need to keep in mind the following DNS configuration issues when you install Active Directory on a home network:

* Root zone entries
* DNS forwarders

Client Connections : Client connections are of prime importance when you look up into Active directories. To prevent any issues of active directories in client connections, the clients should connect to the Active Directory domain controller using an internal network on a second network adapter. This helps clients to obtain an IP address from your Internet service provider (ISP). To achieve this configuration with a second network adapter on the server connected to a hub you can do it with the help of above point of IP address. You can use NAT or ICS to isolate the clients on the local network. To ensure the optimum DNS connectivity The clients should point to the domain’s DNS server. The DNS server’s forwarder will then allow the clients to access DNS addresses on the Internet.

High-Encryption Pack and Internet Connection Software : The most important aspect of any web based technology is Internet connection. Basically the softwares which must be used, if your Internet connection requires the installation of an Internet connection program from your ISP, be aware that older versions of these connection programs that are not specifically designed to work with Windows 2000 may cause startup issues if you install them on a Windows 2000-based computer.