Jan 192014
 

Article by Rahul Panwar first posted on http://linuxexplore.com/

A chroot on Unix operating systems is an operation that changes the apparent root directory for the current running process and its children. A program that is run in such a modified environment cannot name (and therefore normally not access) files outside the designated directory tree. The term “chroot” may refer to the chroot(2) system call or the chroot(8) wrapper program. The modified environment is called a “chroot jail”. From Wikipedia.

Why it is required? If you want to set up your Linux box as a web hosting server for its users, you may need to give SFTP access. But they can get access to whole system Linux tree, just for reading but still very unsecure. So it is mandatory to lock them in their home directory.

There are many other applications, it’s just a common example, so lets start its configuration.

Continue reading »

flattr this!

Jan 142014
 

Sometimes you need to clone partitions on your hard drive for various reasons, hd damaged, creating a RAID 1 or something similar, then it is often tedious and impractical to perform the operation using the normal tools like fdisk, in this case you can use sfdisk.

As reported in the manual:

sfdisk is a non-interactive program to edit the partition table, which is useful for creating scripts. The normal use of this service program involves the preparation of a file containing the instructions on the partitions to be created within a disk specified explicitly. Even if there is a special syntax for these instructions, it may be convenient to use since it is obtained from a query with the same sfdisk, as will be shown.

Continue reading »

flattr this!

Jan 132014
 

I use ssh everyday and it’s my main tool to connect and manage servers, so I’m always interested in articles about ssh.
Today I present an interesting article on this subject, written by Corey Quinn and posted on the sysadvent blog

Every year or two, I like to look back over my client’s SSH configuration file and assess what I’ve changed.

This year’s emphasis has been on a few options that center around session persistence. I’ve been spending a lot of time on the road this year, using SSH to log into remote servers over terrible hotel wireless networks. As a result, I’ve found myself plagued by SSH session resets. This can be somewhat distracting when I’m in the midst of a task that requires deep concentration— or in the middle of editing a configuration file without the use of screen or tmux.

ServerAliveInterval 60

This triggers a message from the client to the server every sixty seconds requesting a response, in the event that data haven’t been received from the server in that time. This message is sent via SSH’s encrypted channel.

Continue reading »

flattr this!

Jan 062014
 

An interesting and detailed howto on apt, first posted on linux mint community tutorials

Intro by Wikipedia:

The Advanced Packaging Tool, or APT, is a free user interface that works with core libraries to handle the installation and removal of software on the Debian GNU/Linux distribution and its variants. APT simplifies the process of managing software on Unix-like computer systems by automating the retrieval, configuration and installation of software packages.

When you launch Software Manager or Update Manager or Synaptic Package Manager, you’re using APT via different GUIs. But you can control APT even via command lines in an easy and quick way.

Continue reading »

flattr this!

Jan 032014
 

youtube-dl_logo
In the past I’ve published some articles regarding how to download music from youtube with the program YouTube to MP3, or videos with the programs xVideoServiceThief and flareget, they all accomplish the work with graphical interfaces, and this can be a great plus for many users, but others could prefer a simple command line program that can easily download videos and optionally extract the audio in a specific format: youtube-dl.

Continue reading »

flattr this!