3 Methods of Linux System Administration and Why Linux Commands Are Best – Linux Training Online

When you are a new user needing to get Linux training, it is often confusing to decide what to focus on.

Should you learn how to use Linux for just one distribution (a.k.a. version, distro)?

Should you focus on learning GUI utilities – or should you learn Linux commands for doing system administration?

Linux Commands Training Tips: The Linux System Administration concepts and commands covered here apply to ALL Linux distros, including: Red Hat, Ubuntu, Kubuntu, Edubuntu, Slackware, Debian, Fedora, SUSE and openSUSE.

3 Methods of Linux System Administration and Why Using Linux Commands is the Best Method

1. Using Linux GUI utilities for System Administration

Many Linux distributions have “point-and-click” GUI (graphical user interface) utilities that allow you to do common and popular tasks, like manage the file system, create Linux users, and manage user and group permissions.

However, these GUI utilities are usually specific to a single Linux distribution.

So, learning how to use a Linux GUI in one distro is basically useless if you have to use a different one later, or if you’re working in an environment with multiple Linux distributions.

Linux Training Tips: To run a GUI utility, you need to have a desktop installed and sometimes one isn’t installed on a Linux server because it isn’t needed. In addition to this, the Linux system administration pros only use commands because GUI utilities are too slow to run and time-consuming to use.

2. Doing Linux System Administration Tasks with Commands that are Specific to a Distribution

The major (popular) Linux distributions all have several commands that are specific to that single distribution. In other words, for each popular distro, there are several commands that are specific that just that version.

For example, a Linux distribution will likely have a command that is used to manage partitions (disk space) and this command is specific to that distribution.

Learning how to use commands that are only available on a single distribution is a huge waste of time – if there is an equivalent GNU / Linux command – and there almost always is.

For example, the Linux fdisk command is a GNU command that is used to manage the partitions on a system and this command exists on all distributions.

So, rather than learn a command that is specific to a single Linux distribution, learn the GNU commands because these commands are common to all distributions.

3. Using Linux Commands that are Common to All Distributions – The GNU Commands

The GNU commands are the most popular Linux commands – and they are common to all distributions.

Linux Training Tips: Linux distributions are rising and falling in popularity all the time.

If you just learn how to use Linux by running the GUI utilities in one distro, and then you stop using that distro, then you have to learn all the GUI utilities of the next distro. If you learn how to use commands, then you learn how to use Linux for all distros!

How can you tell which commands are the GNU / Linux commands?

Get an excellent set of videos that shows you the popular GNU commands and then try these Linux commands yourself. Then you can learn Linux the easy way – by watching it and then working with it!

Understanding Linux Filesystems & Linux Filesystem Types – Linux System Admin Training – Run Ubuntu

The Default Linux File Systems (Filesystems)

The default filesystems that are recognized by Linux are specified in the text file named filesystems in the /proc directory.

Four of the filesystems that are commonly found on a Linux system are: ext2 (old and less common), ext3 (very common), iso9660 and swap.

Some Linux distributions also use other filesystems.

For example, instead of the ext3 filesystem, the SUSE and openSUSE distributions use the reiserfs filesystem by default.

In addition to the above filesystems, by default Linux can also recognize a partition that is a “swap” partition.

Depending on the documentation that you are reading and the command or utility that you are using, “swap” is not typically considered to be a filesystem type. It is a type of partition that is treated by the OS as virtual memory (where hard disk storage space works as though it is RAM memory).

The following is a description of some of the commonly used Linux filesystems.

ext2 (second extended filesystem) supports UNIX/Linux files and directories and allows for long file names (up to 255 characters).

ext3 (third extended filesystem) is the current default filesystem for Red Hat, Fedora and many other Linux distributions. The ext3 filesystem is on the way to becoming the de facto standard for Linux.

ext3 is based on the previous ext2 filesystem. It is basically the same as ext2, with the main difference being that ext3 supports a feature called “journalling”. The greatest benefit of this feature is that it provides a quicker recovery when a filesystem “crash” occurs and a system goes “down” (and stops working).

If files are corrupted on a partition using ext2, then the Linux fsck (filesystem check) utility is run to check the filesystem and repair it and this can take a very long time.

When the files on an ext3 filesystem become corrupted, then the fsck utility is still run to check and repair the filesystem, but this takes much less time due to the journalling feature of ext3.

vfat is the Linux filesystem that is compatible with DOS file names and Windows long file names. In some Linux utilities, “vfat” appears as “fat” or “fat32”.

iso9660 is the filesystem used on a CD-ROM.

swap (a.k.a. Linux swap partition, swap drive, swap space) is a disk partition that is used by the Linux OS as “virtual memory”. Linux uses the disk space that you have specified for the swap drive as though it were RAM (memory chips in your system).

The Linux filesystem type concepts and definitions covered here apply to: Ubuntu, Debian, Red Hat, Fedora, SUSE, Slackware, openSUSE – and ALL other Linux distributions.

Distributing the Processing and Storage Function in Distributed Systems

In distributed system, multiple computers are connected on the network working together as a system. These computer are independent but their collection appears to it users as a single coherent system. Distributed system provides sharing of resources and information. Processes executed on these systems can communicate with one another by exchanging messages over communication channel.

The distributed processing refers to LAN designed so that a single program can run simultaneously at various sites. Most distributed processing systems contain sophisticated software that detects idle CPUs on the network and parcels out programs to utilize them.

Another form of distributed processing involves distributed database, databases in which the data stored across two or more computer systems. The database system keeps track of where the data is so that the distributed nature of the database is not apparent to users.

A distributed database consists of two or more data files located at different sites on a computer network. Because the database is distributed, different users can without interfering with one another. However, the DBMS must periodically synchronize the scattered database to make sure they all have consistent data.

The software system that facilitates the the management of a DDB in such a way that the distribution aspects are transparent to users.

A DDBMS running on a different computer at each site can handle local applications autonomously and participates in at least one global application requiring data from other sites. Communication between different sites via a network is essential for any global application.

The Functions of Such DDBMS are:

To extend communication services to provide access to remote sites and allow the transfer of queries and data across the network.
To extend the DD to store data distribution details.
To provide distributed query processing, including optimization and remote data access.
To extend accuracy control to maintain consistency of replicated data.
To extend recovery services to take account of failures either of sites or of communication links.

Distributed data storage:

There are two approaches for storing data in distributed database.

Replication: The system create different similar copy of any data and each copy is stored on different places. There are two types of replication strategy.
Selective Replication
Complete Replication

Complete Replication: The complete replication strategy consists of maintaining a complete copy of the database at each site. This maximizes accessibility and reliability, but costs of storage and the communications needed for updates may be high.