Linux servers are manufactured to counter high demand of application such as database management, web services and network administration and system administration. Linux servers are more preferred due to its reliability, flexibility and stability. A major part of the IT market is relying over Linux platform. Linux servers now covers 16.8 % of all server revenue; up by 2.5 points over 2009.Linux server market revenue grew 30% to $1.8 billion when compared with second quarter of 2009.It share 16.8 % part of revenue grossed by all servers.
Hardening Linux servers :
A proper procedure and policy is required to maintain a secure computing environment where unauthorized access could be prevented .For making security risks should be assessed. While open source does not hide o/s inner working, but security is the core part of Linux kernel.
Linux servers are secured by External firewalls, SSH hardening and internal privilege hardening. Further some of measures can be applied that are as following:-
- Use PAM to make user control secure. Strong password and authentication controls are critical for host with high number of shell user.
- SELinux should be used while it is complex to configure but it strengthens more granular control.
- You should prevent advancement of tools if there is large no. of shell user.
- Centralized log monitoring system should be arranged and alert must be put over more critical and important log messages.SEC or Swatch like tool should be used.
ShellShock Flaw :
ShellShock Flaw has collected huge media coverage over the time. ShellShock Flaw allows invader to execute bash commands on unauthorized and unauthenticated host. It is basically a mass of vulnerabilities. The risk depends upon how bash interprets environment variables. The systems using Bash Scripts are at the higher risk .Some measures are taken to protect form Shellshock flaw are:-
- Defense in depth should be incorporated for systems that are using bash scripts.
- SELinux and APPArmor should be engaged to limit the access of bash to what user is running.
A required attention is brought to Shell scripting security by shellshock. Migration to languages that have been designed keeping security in mind is essential since need for shell script always exists. A new language Shill has been developed by Harvard researchers with a stress over security but there is a long way to go.
Some other common attack vectors are:-
- Httpd
- Secure Shell
- DHClient
- CUPS
- Sudo
- Firefox
- Postfix
Redhat recently announced its 64 bit ARM architecture designed for datacenters. It has (TDP) thermal design power between 10 and 45watts where as traditional x86 processor has more than 90watts.Direct Server utility bills and data center running cost lowers along with power consumption.
Why Linux?
Linux has been a preferred choice because of its stability feature and better response to concurrent processes. It is able to run over a long period of time without facing any crashes. The basic reason for adopting Linux is TCO (total cost of ownership). Moreover, all configuration changes can be accomplished without rebooting the system thus not affecting irrelevant services. The distributive nature of Linux made it an acceptable choice because it does not need any SI (System identifier). In Linux; the systems are distinguished by IP addresses and names. It runs over any machine architecture and unlike its counterparts which completely depend on Intel-compatible processors.
Linux is a secure and better Operating system as compared to Windows.
Some of the best Linux Distro :
Business Linux Distros
- Red Hat Enterprise Linux: It's a commercially used distro designed for enterprise customers. You can use any of the different addons and variants.
- SUSE Linux Enterprise: Designed for an enterprise and can be used by businesses with different office programs. It runs on various devices and can be used even on critical systems.
Gaming Linux Distros
- SparkyLinux Game Over Edition: If focuses on gaming and comes with a various pre-installed premium and free games, and LXDE desktop, PlayOnLinux, Steam, and Wine.
- SteamOS: Mainly used by gamers as it comes with a Steam client. It is optimized to perform well in any game and comes with in-built sound drivers and proprietary graphics.
General-Purpose Linux Distros
- Fedora : It was developed around same time as Ubuntu by IBM-owned Red Hat. Fedora 21 is the new release known as fedora next. Fedoras has three releases Workstation, cloud and sever, each one is aimed to specific use-cases.Fedora21 server with its Rolekit tool is now focused over server administration and enable administrator to specify server roles .It leverages open source freelPA identity and authentication application providing secure access. The big tool is Cockpit server management which provides small scale server management. It uses a default GNOME desktop environment but users can switch to LXDE, XForms Common Environment (Xfce), Cinnamon, KDE and MATE, and other desktop environments. Its variant ‘Fedora spins', used by people who have specific requirements.
- CentOS Community Enterprise Operating System or CentOS: Built by the Red Hat community and is a rebuild of the Red Hat Linux Enterprise and is a free version of the distro.
- Ubuntu : It is one most prevalent and famous Linux Distro .it is preferable for its user friendliness. Its name is derived from a South African philosophy of ‘universal humanism’. Besides it includes various open source programs like email client thunderbird, web browser Firefox, and Libreoffice. Moreover a user can access more software from Software center Repository. It is a Debian-based operating system designed for hybrids, desktops, and laptops. GNOME is used as the default desktop environment. It's regularly patched and improves with every new release. For users moving from macOS, it's the best Operating System.
- Debian : It is one of original Linux Distro developed almost three decades ago. It is named over its founder Ian Murdock and Debra. It comes with a default GNOME desktop environment, but can also be used in the FreeBSD kernel. Developers are working to make it compatible with other kernels like the Hurd. Some Linux distros, such as Raspbian and Ubuntu, are based on Debian.
- OpenSuse : OpenSuse was based off a German acronym Suse (Software and system evolution) built by Linux for various projects. The project was developed by the US firm Novell for allowing to work over its development by them who are outside the firm. It offers high configurable feature, and huge scope of customization. An administration program called YaST controls and monitors the installation, package management, and other functions. It's used by both beginners and by experienced Linux users.
- Gentoo Linux: It can be used on any desktop as is compatible with multiple requirements, and its performance and versatility make it one of the best versions of Linux OS. It Portage, an advanced package management system. The users gain complete access to the system and control it the way they need to.
- Slackware Linux: It's a Unix-like distro built specifically for simplicity and security and used for server and file management. It has web, FTP, and email servers.
- Mageia: Developed by a non-profit fork community. It has various features that a major desktop environment should have. The default desktop used by this distro is GNOME and KDE.
- SparkyLinux: It evolved when the developers were testing the Debian version of Linux. It has a customized lightweight LXDE desktop and can be used with any customized desktop.
Lightweight Linux Distros
- Linux lite: It's based on the Ubuntu LTS releases and has a very minimal footprint which means you can use it on a PC with 512 MB RAM and 700 MHz CPU. It uses a simple and clean Xfce desktop and also uses a simple Windows-style Start menu which makes any Windows user feel at home. The users can use this version on an old computer or laptop if they want to maximize battery life.
- Arch Linux: Recommended for beginners since it requires some hands-on experience with the operating system. This Linux distribution was developed with user experience in mind, aimed at keeping things simple and easy. It is updated regularly through patches. The Pacman, a custom-made package manager makes it easy for users to build, share and modify packages.
- Puppy Linux: It uses a small distribution to run older laptops or computers, and even on computers or laptops without hard drives. Mostly used by companies and individuals as a tool to remove malware.
- Manjaro Linux: An easy-to-use, fast, user-friendly, lightweight distribution that uses the benefits of Arch Linux. It uses Xfce as the default desktop but users can switch to other options depending on their comfort.
- NuTyX: It enables a user to customize the OS using the concept of the collection, as it allows to ship bloatware-free and barebones across the OS. A user has a choice for everything to use as a selection of window managers or desktop environments. A user can develop a user-determined operating system that has multiple possibilities.
- Bodhi: An Ubuntu-based distribution operating system, having a beautiful and lightweight Enlightenment desktop. It can be customized and comes with applications and themes.
- Xubuntu: The derivative of the Ubuntu distros uses a lightweight and elegant Xfce desktop. The users can use it on different notebooks and laptops with low specs. It does not need many system resources hence used on old devices.
- Lubuntu: Based on Ubuntu, and is perfect to use on laptops or desktops. It uses a lightweight desktop environment and has in-built lightweight applications designed for speed and energy efficiency to maintain the device’s battery life. The users can use this OS on old mobile devices, computers, and netbooks. It does not need high-speed RAM and has few system requirements.
Multimedia Linux Distros
- Fedora Design Suite: A spin-off of the Fedora design suite comes with pre-installed artistic applications and tools used for art and illustration. The design suite comes with GIMP and Inkscape. The distro is focused on DTP.
- Ubuntu Studio: Released in 2007 and is the default choice used by Linux creative users like photographers, music producers, designers, and other users. It comes with an Xfce desktop environment and has low kernel latency. Therefore, everything is geared towards the production of media.
Linux Distros for Security and Recovery
- Qubes 3.2: This distro is known for freedom, security, and various privacy features. It also comes with sandboxes that allow users to separate the application and hardware when they perform different functions.
- Kali Linux: Earlier known as BackTrack is a penetration testing Linux distro that is used often by the online security community. This is a Debian-based distro which makes it easier to perform various forensic tasks.
- GParted: A single-purpose dedicated and standalone distribution operating system that makes it easier to partition hard drives using a graphical interface.
- Parted Magic: It is used to manage disk space on the system. The users can partition the hard disk and copy the information across different servers as the OS's primary applications. This makes it easier to secure erasing and recovery of data.
- Tails: A Linux distribution operating system developed around the idea of security and privacy. A user can use it through a USB stick, SD card, or DVD. Furthermore, use anywhere without worrying about leaving a trace. To maintain anonymity everything performed on the system is routed through a different router (called the Onion Router or TOR). A user can also use different cryptographic tools to protect all the information you send or receive from prying eyes.
Linux Distros for Beginners
- Endless OS: It comes with multiple applications and is best recommended for new users using open-source operating systems.
- Linux Mint: It is a modern, elegant, reliable, and powerful distro that is easy to use. Based on Ubuntu was developed with the idea of a software manager in mind. It's been one of the top-rated Linux operating systems since 2011. It comes with various desktop options like its default Cinnamon desktop. Alternatively, users can use KDE, Xfce, or MATE. It is a less prominent distro and has been forked in its second iteration from an earlier release of Ubuntu. The developer behind Linux mint decided to release an alternate version of Debian and now supporting various streams for those who want to incorporate it in different hardware conditions. It comes with Many software which will be needed out of the box despite being less dominant than its industry rivals.
- Deepin: Ubuntu-based distro with a stylish DDE or Deepin Desktop Environment inspired and developed based on macOS. It's simple and intuitive and features a variety of system settings panel displays. It also has a software center that is easy to use and has tools that are far superior when compared to other Linux distros.
- Pop!_OS: Ubuntu-based operating system manufactured based on Linux hardware manufacturer system 76. It uses a GNOME desktop as the default environment and has a theme that users can change. The colors vary depending on the brand identity of System 76. It has an application and installation browser, making it easier for users to install the required Linux applications. Some applications may not match the theme, but this is an easy-to-use distro for a beginner.
- Zorin OS: Designed specifically for beginners based on Ubuntu and has several applications, which are like Windows applications. It can ease the transition from using other operating systems to Linux. The users can also configure the desktop on the Zorin OS distro to resemble Linux, Windows, or macOS.
- Elementary OS: Ubuntu-based distro developed in 2013 has simple and beautiful default applications, features, productivity apps, and tools. These applications maintain the operating system's aesthetic appeal, such as using the Epiphany web browser and Mail for email. The users can change the desktop layout so it matches that of a macOS.
- RoboLinux: It provides a better or easy solution to switch from Windows to Linux and vice versa. It allows you to set up a Windows virtual machine easily on the user's device. A user can set up Windows XP and later versions easily on RoboLinux and can run Windows applications anytime. This prevents dual booting.
- Kubuntu: Popular Ubuntu distro uses a KDE desktop as the default environment. It is the same as Ubuntu and has the same releases as Ubuntu.
- Raspberry Pi: An extremely common and popular Linux machine that uses an ARM processor instead of AMD or Intel 32-bit or 64-bit CPUs. It is for this reason the Raspberry Pi Foundation worked on developing specialist distros.
- Raspbian Stretch For Raspbian Pi: Developed by Raspberry Pi Foundation. The default operating system used is the Debian-based Raspbian Stretch. It is an ARM Linux distro and has multiple programming tools and applications. A beginner can use these tools to learn more about coding on Linux. Raspbian also has LXDE-based PIXEL environments, making this distro the best option, especially if you are using Raspberry Pi.
- DietPi: A very light Debian-based operating system can be used on all models of Raspberry Pi. The users can use it on single-board computers. DietPi only needs 1 GB storage, while others need 2 GB or more.
- Kano OS: Focuses more on coding aimed at helping children learn more about how to code. The system comes with an interactive user interface and gives children the tools needed to code without too much fuss.
There are many organizations that advocate for Linux adoption. In May 2014, W3techs surmised that 67.5% of top 10 million websites run over some form of UNIX whereas Linux is used by 57.2% of a website that uses UNIX. The (IFOSSF) international free and open source foundation has decided to accelerate and promote the adoption of FOSS (free and open-source software) through civil society partnership and research.
Some other are:-
- Asian Open Source centre (AsiaOSC)
- Software LivreBrasil (a Brazilian organisation)
- Free and open source foundation of India and china.
- IBM with its Linux marketing strategy
- Linux users group
Oracle has released a secure boot version of its Linux, which has a chain of trust in the boot process. When the bootloader is loaded by firmware, it checks the authentication signature of the bootloader with a signature key stored in the firmware before proceeding.
Linux software developers are striving hard to expand Linux storage and file systems. In recent years flash memory has been evolved as server primary storage and persistent memory is rendering us storage that works at DRAM speed.
- BTRFS : BTRFS is a copy on write file system that emphasis over fault tolerance and easy administration. It has advantage of handling numerous small size files and huge size files such as 16 EiB, multi-storage device support, and baked in RAID. It has extent based storage system, space-effecting indexing directories, Writable and read only snapshots, separate internal file storage system modules. The BRTFS development team is working over object level stripping and mirroring, compression methods and in band deduplications.
- CephFS : It is POSIX-compliant file system that utilizes ceph storage cluster to store data. It provides a distributed storage and file system, which relies over resilient and scalable storage model. Some expert says that CephFS is not completely ready yet. Being a distributed system, Ceph FS has to deal with multiple writes from multiple clients. Consequently that results in file lock-in situation.
So, Although Linux has many file systems and is able to use any kind of storage. Still, there is a lot of work which is to be done.