Linux Mint 17.2 Rafaela available for download

In today's open source roundup: Download the release candidate for Linux Mint 17.2. Plus: How to defrag your Linux computer. And a guide to understanding systemd

Linux Mint 17.2 release candidate available

Development on Linux Mint 17.2 is humming right along, and now you can download the official release candidate. Expect to see a final release of Linux Mint 17.2 sometime in July. Until then you can run the release candidate to get an idea of what to expect from Linux Mint 17.2.

Marius Nestor reports for Softpedia:

After announcing the release of the Cinnamon 2.6.8 desktop environment earlier today for the upcoming Linux Mint 17.2 (Rafaela) operating system, it would appear that Clement Lefebvre already published the ISO images of the Release Candidate (RC) version on the main servers.

The final release of Linux Mint 17.2 will be made available for download sometime in July 2015 and it will be a long-term support release supported with software updates and security patches until year 2019. As far as we know, it will be based on Ubuntu 14.04 LTS (Trusty Tahr).

More at Softpedia

How to defrag your Linux computer

Windows users are familiar with the need to defragment their hard disk, but many Linux users are unaware of how to do it. How To Forge has a helpful tutorial that shows you how to defrag your Linux computer.

There is a common misconception among GNU/Linux users that our systems never ever need to be defragmented. This stems from the success of the journalized filesystems used by most distributions including EXT2,3 and 4, JFS, ZFS, XFS, ReiserFS and BTRFS. All of these boast smart ways and techniques in regards to the files allocation in the disks, minimizing the fragmentation problem to a point that there is practically no reason to defrag even after many years of installing and uninstalling applications and libraries in the same system. Fragmentation though can still be an issue though, especially for users that use space limited disks that may not offer many file allocation options.

Here's a bulk description of how the (Linux) file allocation procedure works: files are stored in multiple places in the disk, leaving huge unwritten space between them, allowing them to grow unobstructed over time if needed. This is in contrary to filesystems like the Windows' NTFS which places files next to each other consecutively. If the disk gets more crowded and a file needs more space to grow by staying in one piece, Linux filesystems attempt to re-write it completely on another sector that has enough space to store it as a whole. This way, everything is kept clean, tidy and in one piece each. Confined space though, causes this file “maneuvering” to get more challenging with time. Here's how to deal with this problem and how to actually defrag your Linux system.

Now, the first thing that you'll need to do is get a defragment tool installed. There are many defragmenters available for Linux filesystems but I will use “e4defrag” as it is one that will most probably be already installed in your system. Using this tool, you can determine if you have fragmented files and how serious this fragmentation is. To do this, open a terminal and type: sudo e4defrag -c /location or /dev/device. Below, I have scanned my /home folder for fragmented files and actually found five of them. My fragmentation score though is quite low so defragging won't do much different in my system's performance in that case. If this outputs a score over “30”, then defragging would be a good idea.

More at How To Forge

Understanding systemd

The systemd controversy has raged for a long time in the Linux community. But how many people really understand systemd itself? The Cyberpunk blog has a detailed and informative overview of systemd that is worth reading.

systemd is a suite of system management daemons, libraries, and utilities designed as a central management and configuration platform for the Linux computer operating system. Described by its authors as a “basic building block” for an operating system, systemd primarily aims to replace the Linux init system (the first process executed in user space during the Linux startup process) inherited from UNIX System V and Berkeley Software Distribution (BSD). The name systemd adheres to the Unix convention of making daemons easier to distinguish by having the letter d as the last letter of the filename.

The design of systemd generated significant controversy within the free software community, leading the critics to argue that systemd’s architecture violates the Unix philosophy and that it will eventually form a system of interlocking dependencies. However, as of 2015 most major Linux distributions have adopted it as their default init system.

systemd is not just the name of the init daemon but also refers to the entire software bundle around it, which, in addition to the systemd init daemon, includes the daemons journald, logind and networkd, and many other low-level components. In January 2013, Poettering described systemd not as one program, but rather a large software suite that includes 69 individual binaries. As an integrated software suite, systemd replaces the startup sequences and runlevels controlled by the traditional init daemon, along with the shell scripts executed under its control. systemd also integrates many other services that are common on Linux systems by handling user logins, the system console, device hotplugging, scheduled execution (replacing cron) logging, hostnames and locales.

Like the init daemon, systemd is a daemon that manages other daemons, which, including systemd itself, are background processes. systemd is the first daemon to start during booting and the last daemon to terminate during shutdown. The systemd daemon serves as the root of the user space’s process tree; the first process (pid 1) has a special role on Unix systems, as it receives a SIGCHLD signal when a daemon process (which has detached from its parent) terminates. Therefore, the first process is particularly well suited for the purpose of monitoring daemons; systemd attempts to improve in that particular area over the traditional approach, which would usually not restart daemons automatically but only launch them once without further monitoring.

More at Cyberpunk Blog

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