One of the essential reflexes every new Linux user must develop is the reflex to search for information when something's amiss. But despite the fact that we live in a connected world, with search engines, wikis and huge quantities of information at our fingertips, it's always good to have the info we need already installed on the system we're working on. This makes for easy and fast access, and also for higher availability, should we lack access to an Internet connection. Besides, one can't always trust what one finds on the Web, and the manual pages are available in a consistent form, ready to answer questions to the impatient. One of the design philosophies standing behind Unix, and by inheritance Linux as well, is that the system should be well documented. This is how man pages came into being. While all Unix-based OSs have man pages, there are differences between them, so what works on Linux might not work on Solaris, for example. There is an issue, though: the writing style of these pages is terse, minute, impatient to the newcomer, so you might want to read a manpage a few times until you get accustomed.
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Although you may think that you have learned to master Linux command line with bash shell, there are always some new tricks to learn to make your command line skills more efficient. This article will teach you a few more basic tricks on how to make your life with the Linux command line & bash more bearable and even enjoyable.
Bash Command History Expansion
This section will mostly deal with bash shortcuts in combination with three bash history expansion characters "!", "^" and "#". Bash Command History Expansion character "!" indicates start of history expansion. The "^" is a substitution character to modify a previously run command. The last optional character is "#", which denotes the reminder of the line as a comment.
Repeat last command
$ echo Bash Shortcuts
echo Bash Shortcuts
!! is probably the easiest and most popular bash shortcut, which simply shows and executes your last entered command.
Read more ... WARNING: This process will erase all information from the Chromebook hard drive. As with all firmware flashes, there is a chance of something going wrong, rendering the device useless. Proceed at your own risk.
Chromebooks are everywhere. Google’s little Linux based PCs have been booming since their introduction several years ago in everything from homes to businesses, and even educational settings. Many users, especially Linux users, can’t get past the fact that the devices are hopelessly hamstrung by their ChromeOS operating system which both cuts down on the number of apps the device can run and makes it dependent on an Internet connection to get anything done.
So, what does a Linux user believing in the potential of their little (sort of)Linux laptop do? Break everything Google did. In many cases, Chromebooks are supported by the FOSS Coreboot project, meaning that there is a completely unlocked, free and open source version of the Chromebook BIOS just waiting to be installed. With a few relatively simple steps, that \$300 Chromebook can become a full fledged Linux laptop running just about any distribution. It should be noted that you should check which type of processor your Chromebook is running first, this method only supports Intel based Chromebooks. Another thing to keep in mind before getting started is that there are a ton of different Chromebooks. This method was tested with the extremely common Acer 7XX series, but it should work(maybe with subtle differences) on other Chromebooks as well.
Read more ... March 12, 2013
by Lubos Rendek
Whether you are administrating a small home network or an enterprise network for a large company the data storage is always a concern. It can be in terms of lack of disk space or inefficient backup solution. In both cases GlusterFS can be the right tool to fix your problem as it allows you to scale your resources horizontally as well as vertically. In this guide we will configure the distributed and replicated/mirror data storage. As the name suggests a GlusterFS's distributed storage mode will allow you to evenly redistribute your data across multiple network nodes, while a replicated mode will make sure that all your data are mirrored across all network nodes.
What is GlusterFS
After reading the introduction you should have already a fair idea what GlusterFS is. You can think of it as an aggregation service for all your empty disk space across your whole network. It connects all nodes with GlusterFS installation over TCP or RDMA creating a single storage resource combining all available disk space into a single storage volume ( distributed mode ) or uses the maximum of available disk space on all notes to mirror your data ( replicated mode ). Therefore, each volume consist of multiple nodes, which in GlusterFS terminology are called bricks.
Although GlusterFS can by installed and used on any Linux distribution, this article will primarily use Ubuntu Linux. However, you should be able to use this guide on any Linux Distribution like RedHat, Fedora, SuSe, etc. The only part which will be different will be the GlusterFS installation process.
Furthermore, this guide will use 3 example hostnames:
- storage.server1 - GlusterFS storage server
- storage.server2 - GlusterFS storage server
- storage.client - GlusterFS storage client
Use DNS server or /etc/hosts file to define your hostnames and adjust your scenario to this guide.
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Steganography is the art of hiding messages within other messages or data. Most commonly we see this utilized with pictures. This is probably encryption at its finest.
Mostly because it doesn't look like usual garbled text that we are used to seeing with encryption. The changes made by Steganography are so slight the human eye cannot perceive them. Even trained cryptographers may have an encoded message inside a picture and be unaware of it. There is a very deep science to this. Usually this is done by flipping parity bits at the binary level. While it is great to learn how this works, sometimes it can be a very tedious job. Fortunately for us there is a tool that will take away most of the grunt work.
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