If you are used to Windows operating systems, you know about the Shut Down command. Graceful reboot in WHM is similar to the Windows shut down command: it will stop every running process, save states, synchronizes the file system and so on. When everything is done, it will restart the server. The graceful reboot in WHM is very similar to the reboot command on Linux systems, but it’s not exactly the same. For example while the reboot command broadcasts a message, informing every logged in user about that the system will soon restart, WHM’s Graceful Reboot will not do that.

Forceful Reboot on the other hand will only attempt to stop the running processes. If it fails, it cares not about it. With a bit of exaggeration, it’s like when you push the Reset button on your PC. You should only restart your server this way if the Graceful method doesn’t work for some reason. So, when you try to reboot your server, the actions to take are the following:

1. Try the Graceful Reboot
2. If the tool reports the Graceful reboot has failed, you try the Forceful reboot

When is advised to reboot a server? The occasions are extremely rare. The Linux systems are not Windows to reboot the whole server just because you installed DirectX. I really think that the only reason to reboot if you’ve done kernel update.

In the Networking section of WHM you will find by default 3 gadgets:

1. Hostname
2. Nameserver IPs
3. Resolver configuration

Each of these gadgets is extremely important both for you and for the server. Especially if you want the server to be publicly available.

Let’s see the first gadget, Hostname:

The hostname always has to be unique, this is the name of your server. Usually this name, nickname if you like is chosen from the Greek mythology, for example Zeus, and this name is snapped to a fully qualified domain name owned by you, like example.com. This domain name will have to use the server’s nameservers, this will be the first domain you will add to the server. Usually you have to specify this domain name when you order the server. So, a hostname will look like something like this:
zeus.example.com
But it can be very well hera.example com or sinatra.example.com, it doesn’t really matter. The only thing which matters is that this hostname will have to be unique on the server, you will not be able to use it for traditional website access or any other thing, it’s the server’s name.
This hostname can also be used to access cPanel and WHM, so in conformance with the applicable RFC (1035 if am not mistaken) this hostname should never begin with a number, nor end with a hyphen (-).

Nameserver IPs:

This is very important gadget as well, if you want your server to be publicly accessible. What are nameservers? Nameservers tells a client on which IP a website can be found. They are part of the DNS. Internet works based on IPs (like 127.0.0.1), but remembering IPs is hard. For example is more likely you remember www.Google.com than 72.14.205.100, which is one of Google’s IPs. So, the big guys invented domain names like google.com. This is what you type in the address bar of the browser to arrive on Google’s website and perform a search to find out what kind of underwear did Britney wear yesterday.
But the internet still works based on IPs, and nameservers are who basically translates the domain names in IPs. OK, I’ll try to explain this. Imagine a conversation between your PC and the nameserver, like this one:

You: Hey, gTLD nameserver. Do you know where can I find google.com?
NS: Hello, sure. It’s located on the 72.14.205.100 IP. Go there.
You: Thanks!

Don’t imagine for a second that it’s this simple, it’s way more complicated as there are at least 2 other men-in-the-middle before you get that info.
So, the nameservers your server will manage will also have to have — if possible — a unique IP. You will see, depending on how many IPs you got with the server, at least 1 IP. It’s the nameserver of the private network. If there are more than one, each is an existent namesrver. To delete a nameserver, just click the small cross on its right.
To create a new nameserver, put its name in the box below the table containing the IP(s). It will create the nameserver and will assign the next available IP to the name. The name you choose also has to be in conformance with the applicable RFC.
After you created the nameserver on your server, you will have to go to your registrar and register the nameserver. Since your server is not authoritative, you can’t do this without a registrar.

Resolvers’ configuration:

This is a wizard through which you can manage your /etc/resolv.conf . The IPs you will put here are also very important as they are used for dns resolution. When you leased the server, the datacenter most likely provided you at least one nameserver IP you can use. The problem is that you should use two. The first is the primary, the second is for backup. If these nameservers are down, your server is likely will have difficulties querying the MySQL databases, so if the DC didn’t provide you nameserver IPs you can use, choose carefully. But your best option is to contact the datacenter and pick their brains until they give you at least one IP of a DNS.
Also, while the server may function properly without any nameserver IP in the resolv.conf, the connections made to the server will be extremely slow.

WHM has 3 main sections and each section is basically a frame.
On the top of your screen you will see the logo of WHM. Additionally this frame will also contain some navigation links, some info about the server software and OS version. Probably the most important part of this frame is the server load in the lower right corner. There are always three numbers which represents the system load during the last one, five, and fifteen minute periods. This is not a percentage, it’s just a value. If it’s below 1, you’re good because that means that the processor can handle the job and there are no processes waiting. If it’s slightly above one, then you might have to think about (for example) script improvement; in the case it’s way above 1 you might have to think about, for example adding another processor to the system. If it’s an incredibly high number, for example over, let’s say 30, then you have great issues. Usually under a DOS attack is increased that high, but it can also mean that there are too many MySQL queries in a script which is accessed numerous times per second. But for debugging, always check the number of concurrent connection and whether they are legit or not. If you have more than one processor, divide the load with the number of the processors.

Below the top frame, by default you will see a bunch of icons. These are the shortcuts to our server-management gadgets. When you click on an icon, in this frame will be the gadget loaded. Alternatively, clicking on a link on the left side of your screen also updates the right, big frame with the tool you selected.

And finally, on the left you will see a long, scrollable list containing all the in-built tools, or gadgets if you like. This is the most important for us, because by my experience, this is the easiest way to reach the gadgets. The gadgets or tools in WHM are grouped in — by default — 30 categories. I will list the 30 categories, if it’s a hyperlink, means that there’s a guide available for it. So, the categories are:

1. Server Configuration
2. Support
3. Networking Setup
4. Security
5. Server Contacts
6. Resellers
7. Service Configuration
8. Languages
9. Backup
10. Cluster/Remote Access
11. System Reboot
12. Server Status
13. Account Information
14. Account Functions
15. Multi-Account Functions
16. FrontPage
17. Transfers
18. Themes
19. Packages
20. DNS Functions
21. SQL Services
22. IP Functions
23. Disk Drives
24. Software
25. Email
26. System Health
27. cPanel
28. SSL/TLS
29. Restart Services
30. Plugins

These are the categories at the time off this post. These might change over time.

First of all, what’s with this new category? We’ve found that some of the customers we manage servers for wish to take some jobs from us. For example they want to handle on their own the DNS and Apache updates, but there are only a few and very basic guides on how to do these things efficiently, so they fear to take action. We will try to cover the most basic things, spiced with some suggestions to help these customers and anyone who wants to manage his or her own server.

For the beginner server managers, especially if they want to manage UNIX based servers, we strongly recommend to do this job with a server management software. There are dozens of server management software on the market; we recommend you to invest in “cPanel + WHM” because you can save for yourself a lot of pain by managing the server this way. Operating system updates become seamless, account management simpler than to write down your own name.

What is “cPanel + WHM”? It’s the abbreviation of control Panel + Web Host Manager, a server management software licensed, maintained and actively developed by cPanel Inc. It is a web-based tool, written in (mainly) Perl. You need a license to run this software, usually the datacenter offers this license to be leased with the server for a reasonable fee (about $20-$35 USD). You can also buy this license from cPanel Inc. itself, though the price is more scary, about $425 (USD). From now on we will talk only about WHM, because this is the side of the software-package which we will use to manage the server.

This software is limited to the following operating systems: CentOS, Red Hat and FreeBSD. Yes these are all Linux distros. There’s also a Windows based cPanel/WHM, called cPanel Server Suite, but since it’s a Beta release and also requires a whole category to explain everything, we won’t talk about it now. Also worth to mention that currently the only possible way to get this software seemingly is to be part of the development team.
As for operating system, we recommend using CentOS. Reason? There’s no good reason, but our experiences with this Linux distribution: it’s fast, stable, easy to maintain; that’s all.

Next post: WHM -Installation guide

This article is a modified version of one of the 4ugroup server manager’s tutorial. There are no screenshots because most of the things look differently on various OSes. So it would be pointless to show you something which looks totally different on your side.

First, let’s make sure you have the minimum requirements for WHM, and that you will not run into issues caused by 3rd party applications or incompatibilities.
The server specification can be low; cPanel/WHM will run even on a Pentium 1, not sure what will you do with a server like that but whatever. It would be cool if it would have 2 NIC (network interface controller) to have 2 networks available: a private and a public. The private network will be used to connect to the datacenter’s private network on which you can manage the server securely, and the public network will be used to connect to the Internet, it will be used, well, by the public.

You will also have to have an OS already installed. We recommend, again, CentOS for various reasons, but you can choose any other, supported Linux distro, or even FreeBSD. Make sure you have some debuggers and compilers installed. For example a C development tool is required, so is wget if you obtain the cPanel/WHM release from the cPanel Layer. If we’re at wget, do make sure that the uplink to the public network is not used by anything else and is stable. Now make sure the package management system is working properly. And these are the only tools you will need. Note, that you do not have to install Apache, PHP or anything else. They will be installed by cPanel/WHM.
Now should come some words about the partitions. Not in this case, because our experience shows that in 99% of the cases the operating system created partitions are good enough for cPanel/WHM. Worth to mention though, that the /tmp directory should be on a separate partition. This is a basic security measure, if somebody wants me to explain why is this a good idea, feel free to ask in the comments section.
So let’s move forward to networking and hostnames.

First, if the resolvers are working properly. To test it, type the following in the command prompt: dig google.com@yourip , nonetheless to say that you have to replace yourip with an IP from resolv.conf. If it resolves correctly, you’re almost ready to install cPanel/WHM. Before you proceed, make sure there’s no non-vital daemon or process running in the background. We’ve found that sometimes these rogue processes can poison the install, so if there’s running something which you think is unnecessary, just kill it. kill, is a Linux command which is used to end processes. The syntax is kill PROCESS_ID.
Now, think about a hostname you will assign to the server. For this, you will have to have under your management a domain name. Common practice is to choose the nickname for the server from the Greek mythology. Many gives their server’s names like zeus.yourdomain.com or hera.yourdomain.com, but it can be absolutely anything, even britneyspears.yourdomain.com. Just make sure you choose a name which will never be used publicly; this hostname has to be unique.

OK, if you thought you have to do anything else before install, you were wrong; that was all.
If you didn’t yet, login via SSH to the server, or if you’re in the front of the server, just turn it on. In both cases login as root.
Type the following in your prompt:

cd /home
wget http://layer1.cpanel.net/latest
sh latest

Decryption: The first line switches to the home directory/partition, second line instructs the wget software to grab a copy of the latest cpanel from the specified URL, and the last line, install the latest cPanel/WHM. You’re 90% done with the install.

Now open up a web-browser. When you leased the server, you got an e-mail from the datacenter which contains amongst many other things, the primary IP of the server. Type that IP in the address bar of the browser followed by “:2087″. 2086 and 2087 are the default ports on which cPanel and (read this comment) WHM listens on. So your address bar should contain something like this: YO.U.R.IP:2087. In the popup window type root as username and the password associated to this super-user.
Accept everything and click OK on every possible thing until you arrive to a page where are dozens of input fields and questions. You will have to fill out the following fields (there are more, but they can remain empty or they’re already defaulted by WHM):

1. Main Shared Virtual Host IP: this is NOT the primary IP of the server! You got an additional (and at least) 4 IPs with the server. Choose one from those and put it in this field.
2. Server Contact E-Mail Address: your own e-mail address you check at least daily. Here will be sent the emails by the server, containing information you should be aware of
3. Hostname: and here goes that hostname I told you to think about. Most likely you’ve chosen already one, if you didn’t, be creative. As I said, this will be a unique name.
4. Type of Apache logs: combined or access. I’d recommend “access”, this way there will be no unnecessary, additional CPU load on the server. If there’s a problem with Apache, just switch to combined
5. Nameservers: enter at least 2 nameservers in these fields. The more the better. Normally only the first is used and the rest is for backup. Note that these nameservers have to be registered with a registrar before they can work.

And this was all. WHM and cPanel is functional from now on.

To log in to your WHM, just type in your address bar:

YO.U.R.IP:2087

You will need the root password each time you log in, keep it in the nearby but in secure place. If arrives in the wrong hand, serious damages can be made in no time. Also, you should change this password every few weeks. If you change this password, please ensure you inform the datacenter about the password modification because if they can’t login, they can’t help if you need help from them.