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As a System and Network Administrator, there are two Operating Systems that you would likely deal with. They are Microsoft Windows and Unix/Linux.

This post will briefly outline the differences between the two operating systems, and the advantages and disadvantages of them.

How Is UNIX Different From Windows

Free Vs Paid

The UNIX Operating System is Open Source which means everyone can use it, edit it, and pretty much do what ever you want with it. Adopt new ideas; create hacks and a whole heap more. UNIX is basically community orientated. Without the community backing it, it would probably not be nearly as popular as it is today.

Because UNIX is community oriented, there are many different flavours of UNIX. This basically means that users take the base of the UNIX kernel and adapt it to their own needs. Mac OS X is even a flavour of UNIX. Some other flavours include:

• FreeBSD
• Novell
• HP/UX
• Solaris
• Linux
  • Red Hat
  • Debian
  • Ubuntu
  • SuSE

On the other hand, Windows is not, it was coded and created by Microsoft. People are not able to edit it, or change the code in any way.

GUI / Command Line

The main difference that many people will find is that Windows is purely GUI-based where as UNIX is mostly know for its text-based GUI, however it does have a GUI like windows. Many System and Network Administrators prefer to use the command-line in UNIX rather than the Graphical User Interface as the command-line providers more functionality.

Files and File Structure

In Windows, there is a registry which contains system configuration information; files and folders. In UNIX, everything is a file and folders are called directories. Since everything is a file, disks and partitions are mounted as directories, devices appears as files in /dev and so are running processors which appear in /proc.

In Windows, the main folders are C:/Windows, C:/Program Files, C:/Users (for Windows Vista, 7 or C:/Document and Settings for Windows XP). In Unix, the file system layout is very different.

• /boot – Where the boot image files are stored
• /mnt – The mount points for the partitions
• /dev – Files of all the connected devices (USB, Printers)
• /proc – Dynamic process information
• /sys – Dynamic system configuration information
• /var – Log files and system subdirectories
• /tmp & /spool – Temporary files
• /home – User accounts home directories
• /usr & /user/local – A replicate tree for users and contains administrative tools
• /bin & /sbin – Essential system executable files
• /etc – System configuration files
• /share – Common read only files
• /lib & /include – Shared library files and system development

Comparisons

Here are a list of some other comparisons between UNIX and Windows

• Scrips Vs .BAT files
• Shells Vs DOS Command Windows
• /etc config files Vs System Registry
• Shared library’s Vs DLL’s – Dynamic Link Libraries
• Kill Vs Task Manager
• Mkfs / newfs Vs Format and label

Source: MyBestRatedWebHosting

So that is a very short comparison between Windows and UNIX. Just remember, with UNIX, take things slowly, because unlike Windows, you will not be prompted “Are you sure you want to do this”

Introduction  Image Source: Hexablogs

The OSI Network Management model is a model for Network and System Administrators to understand the major functions of network management systems. In this model, there are 5 areas’ of functions which is also known as FCAPS.

The aim of the model is for Network and System Administrators to understand a number of issues and aspects. These include:

• Fault management and recovery
• Configuration and change management
• Accounting User Management
• Performance Management
• Security Management
• Application support
• Integration and Migration
• Planning for growth and acquisitions

Source: Cisco

Fault Management

In Fault Management, the aim is to recognise, isolate and correct, and log faults on the network. As System and Network Administrator, it is your duty to put in place monitoring tools so you are alerted to when faults exist. For example, you want to be alerted when a critical service goes down on the network. If there is a fault, you have to test, fix, update, and repair any faults that occur on the network.

Configuration Management

On of the main issues which causes a system to fault is someone changes a configuration setting. Configuration management facilitates the control of any system configuration both on the hardware and software side. It is important that you record all configuration changes such as what has been changed, why and who did the change; and document system configuration standards. If a fault does arise (it may not be instantly, but a couple of months later), you can track who completed the configuration change.

Accounting Management

Accounting Management is concerned with aspects of the system users. It mainly focuses on charging and billing users for services, and regulating service use.

For example, some organisations charge its users or departments on:

• Printing
• Internet/Bandwidth
• Disk space
• CPU
• Application and Software use

Therefore, it is important to implement ways to properly charge use of IT facilities.

Performance Management

Performance Management involves analysing your network and gather information so that you can prepare it for the future. The performance of a network varies all the time. Most organisations find that the internet is very slow during lunch as many of the staff is browsing the internet, yet in the morning, it will be super quick.

Not only this; but the performance of the network must meet the users and organisations desires. The network and systems services must be available, the speed must be efficient, their must not be bottlenecks and the network should never be used to its maximum capacity for prolonged period of times.

System and Network Administrators must actively monitor the network performance to ensure problems do not occur.

Security Management

Security management is important as you control user access to network resources. Without it, your network will be exposed, as well as all the information and document it contains. As a Network and System Administrator, you are to address network authentication and security auditing to detect and prevent network sabotage, abuse and to prevent unauthorised access.

Administrators are required to:

• Record logs
• Have a Firewall setup
• Control Spam
• Prevent Viruses, Trojans, Spyware
• Upgrade software, install OS patches
• Implement authorisation techniques and password control (which is linked to accounting and configuration management)

Source: Grandlord

You are now aware of the 5 categories of the Network Management Model which is also known as FCAPS. It is a fundamental requirement that all IT infrastructures facilitate this model to protect its environment. Without it, many system downtimes would occur and the organisation may suffer a large financial loss.

Being a System or Network Administrator of a large computer network can be a difficult, and time consuming task. It is not as simple as people might think. Yes, once it is all running well, the life of a Network Administrator may seem easy, but when things go wrong, it can be a living hell. Network Administration is more than just simply connecting a whole bunch of computers together; it is a full time role to ensure that those critical servers and applications remain up almost 100%.

The Main Role Of A Network and System Administrator

As a Network Administrator, your role is to essentially build (integrate existing services), maintain, and upgrade a network of computers, devices, and servers.

If you (or the previous System and Network Administrators) get the build phase right, maintaining and upgrading the network in the future will become much easier. You have to carefully plan your requirements and plan for future growth. In doing so, you have to keep in mind a number of things:

• How many users will be using the system?
• What are the network capacity demands?
• What will the network capacity demands reach in the future?
• What is the geological spread of the network?
• What access controls do you users require?
• What sort of devices and hardware do you require?
  • Desktops
  • Laptops
  • Servers (Web, File, Print, DNS, Backup)
• Do you need remote administration?
• How are you going to support your users?

Source: Wikimeda Common

If the above are planned well, future growth, maintaining and upgrading the network will be much easier. Just remember to analyse your requirements; design and plan the network; implement policies and constraints; and construct and install your network with suitable hardware. Remember to always think of the future. Once it’s all implemented and built, you can administer your network.

When administrating a network, you have to ensure critical services have as close to 100% uptime, because if they are down, your users are going to hassle you all the time – and that can be quite annoying with some users. When maintaining a network, you also have a number of other tasks to perform every day. These include:

• User management
  • Adding, removing and apply security to user accounts and groups
• Hardware
  • Upgrading hardware
  • Replacing faulting hardware
• Software
  • Providing support for applications and operating systems
  • Ensuring critical data is being backed up
• Monitoring
  • Monitor the system
  • Checking logs
  • Conducting security audits
• Support
  • Attending to users help requests
  • Writing documentation

One of the hardest challenges in administrating a network is application support. You can very rarely just add a major application or a network service without any issues. Your network will need to support it. For example, you cannot host a website if you only have dialup internet. Other factors that are needed to be taken into consideration are:

• Does it need to be secured? – Both physically and virtually; internally and externally
• Can the application be supported – Are their people who know how to use the application?
• What risks will it introduce? Viruses, Hackers, privacy?
• Is there enough network capacity to support it? Can you network handle the bandwidth requirements?
• Does data need to be migrated across to the new system from the old system?
• Who should be able to access the new application

Depending on how large your organisation is, these tasks can be broken down in to departments or groups.

As you probably have already found out, you are faced with a number of challenges as it is more than just installing computers and networks. You have to make sure your network:

• Is designed efficiently,
• Is capable of mass management – updating multiple machines at once
• Is secured from threats, and internal and external hackers
• Meets all of your users requirements and needs

And not only for your network, you to have to also:

• Understand the users and organisations needs and wants
• Be able to troubleshoot and fix problems and errors quickly
• Be up to date with the latest technical knowledge and computer news
• Be able to write documentation and instructions

Troubleshooting Problems

Every System and Network Administrator will tell you that they have faced issues that they do not know how to solve, or even know what the actual problem is when they are faced with an issue. That is why they need to have good problem solving skills... and Google!

The basics steps for solving a computer related problem are:

1. Detect the fault of problem
2. Isolate the problem
3. Troubleshoot on how to fix the problem
   • (Make sure you document your steps or make a backup before you do anything)
4. Carry out tests and use tools to diagnose the problem
5. Solve the problem and document a fix

If your network is critical, you cannot just simply reboot a machine, or click a few random buttons to see if you can fix the problem. You have plan how you will fix the problem in the quickest amount of time without causing more disruption to your users, or break it even more.

1. First of all – be systematic. Try the simple things first. If a computer won’t start, make sure the power is turned on.
2. Read logs – Logs provide a lot of information on when things go wrong. So make sure you read and understand what the logs are telling you
3. Pay attention to all the facts
4. Read the documentation – yes, it does help and it’s not always there to take up space in the packaging
5. Talk to others – get on the internet, forums, blogs because other people would likely have faced your issue or know how to help, and ask your colleagues
6. Use test environments – see if you can cause the issue again, and then test the ways on how you can fix it. In a test environment, you know you can’t break the production server any more
7. Know your tools – you usually need something to work out how to fix the problem, or even to find out what the problem actually is. You might not know you have a virus if you don’t conduct a scan
8. Work out the root cause of the problem – hardware failure, user interaction, external event?
9. Have a backup in place – make sure that you can restore the system to what it was like before the problem
10. Do it quickly – Users are being affected and can have a large financial loss to the organisation if the system is down. Fix it first, and then discuss the politics

Source: FutureOfRealEstateTechnology

Change Management

One tip I would like to bring up in System and Network Administration is Change Management. Change Management is very crucial to follow correctly, especially in large organisations. Although it may seem like a waste of time, it is very important step to do. Change Management essential records every change you do (and plan to do), allows you to get permission from bosses (in case something goes wrong) which than allows you to implement a change.

The steps in Change Management are:

• Note the change – what are you actually going to do?
• What are the repercussion – what effect will this Change have, who is going to be affected and when?
• Note the back out plan – if something goes wrong, can the Change be reverted back to the original configuration?
• Revise the policy – are you actually allowed to implement the Change – does your organisation support it?
• Inform impacted users – make sure that all users who will be affected are aware of this change so they don’t call you up saying their system is down
• Make the change/Do the work – disable (take down) services if required
• Inform users that change it is done

A while ago, Virgin Mobile was updating their CRM system which entailed a weekend outage that would affect a number of users and its services. Customers were aware of the change, and were encouraged to plan for this change. One of the services to be affected was mobile phone and SIM card activations. I purchased a phone during the upgrade weekend for my mum, which meant I couldn’t activate the phone. In the mean time, she wasn’t able to use her mobile phone. To make it even worse, Virgin Mobile had problems with the system upgrade, and the system was down for a further 1.5 days. A lot of customers, including myself where unhappy as the change took longer than it should have, and were impacted. Reports on forums, a lot of customers left Virgin Mobile due to it.

The Skills Required for System and Network Administrators

Not everybody has the required skills to be a System and Network Administrator. For example, a person who designs website layouts may not particularly know how to setup a web server. So what are some of the skills that a System and Network Administrator should know?

• UNIX – how to use, install, configure and run
• Scripting – shell, bash, C++, Java
• Network – TCP/IP, Hardware, Communication, Network Standards
• Infrastructure – DNS, DHCP
• Storage – SAN, NAS, NFS, CIFS
• Directory Services – LDAP, WINS, NIS
• User Services – Databases, e-Mail, Office Tools, Web Tools
• System Implementation
• System Troubleshooting
• Security Concepts
• Communication

So that is a brief introduction into the life of a System and Network Administrator. It can be a very difficult task, especially when things go wrong.

In the next few months, I will be looking into “Network and System Administration”. I will be writing about a number of topics providing information, definitions, and techniques all related about administrating systems and networks.

This page will act as a table of contents for each post.

• An Introduction To Network And System Administration – The main role of a network and system administrator, troubleshooting problems, change management, the skills required for system and network administrator
  • This article focuses on what it is like to be a system and network administrator, some of the tasks involved, and why it is crucial to have 100% uptime (or close to it) on critical services
• The OSI Network Management Model – fault management, configuration management, accounting management, performance management, security management
  • The OSI Network Management model is a model of the major functions of network management systems. This post outlines the importance of each section, also known as FCAPS
• A Brief Comparison Between UNIX and Windows for a System and Network Administrator – How is UNIX different from Windows
  • This article outlines a number of reasons why UNIX is different to the Microsoft Windows Operating System