Archives for : Linux

Distributed storage on Debian made easy with GlusterFS

GlusterFS is a mature, elegant and powerful distributed filesystem targeted at very high capacities and availability. Sponsored by Red Hat Inc. and included in their storage server solution, this open-source software is kindly available for some other Linux distributions package system or as sources.

Unlike many other distributed solutions, there is no need to have many computers in order to have a taste of Gluster ease of use. A few minutes to spare is fairly enough to do it on your own computer. Note also that only the amd64 architecture is present in the repository and thus the following apply to those 64 bits machines only.

First, add the GnuPG key for the repository and the corresponding entry for APT:

wget -O - | apt-key add -
echo "deb [ arch=amd64 ] wheezy main" >/etc/apt/sources.list.d/glusterfs.list

The arch option is useful, as documented in Multiarch specs in case you’re using multiarch with some foreign architecture package already installed.

Next, update the packages database and install both the server and client packages:

apt-get update
apt-get install glusterfs-server glusterfs-client

Now, either you have a whole disk or partition available or, like me, you don’t. Let’s just use a file as our disk then. In any case, the goal is to format our disk, preferably with XFS, and mount it.

Doing it with a disk or a partition is left to the reader’s discretion and knowledge ;] with a file, it’s as easy as (thanks to this libgfapi doc):

truncate -s 5GB /srv/xfsdisk
mkfs.xfs -i size=512 /srv/xfsdisk
mkdir -p /export/brick
echo "/srv/xfsdisk /export/brick xfs loop,inode64,noatime,nodiratime 0 0" >> /etc/fstab
mount /export/brick

Last tip before starting our cluster, as Gluster doesn’t want us to use localhost as a valid node hostname, we add a definition for another name on our loopback network:

echo " localnode" >>/etc/hosts

Now the real work with Gluster may begin; first, create a directory in the dedicated mount-point and add it as a brick on our upcoming volume:

mkdir /export/brick/b1
gluster volume create test localnode:/export/brick/b1

Last, start the volume and enjoy, it’s working.

gluster volume start test

And now…? Now you may play a little with the powerful gluster CLI, gluster help will output the available commands. You may also be a client of your cluster storage (yes, you can) by simply mounting the volume somewhere, like:

mkdir /mnt/gluster
mount -t glusterfs localnode:/test /mnt/gluster

Quake Live… less

As announced by SyncError the 17th of this month, QuakeLive is now a standalone game (not in the browser anymore, as a regular Quake 3) but (here comes the fail) for Windows only. No more Linux or Mac support for this game, unless a Linux developper is hired by id (sic).

Highly commented on this ESR article, some people may be able to launch and run the game using Wine or a Virtualization solution. I personnaly failed to run the installer using wine and don’t have a working OpenGL with VirtualBox; too bad.

Following the departure of John Carmack, this is probably the last step showing the decline of id Software since they have been bought by Bethesda. Somewhat a shame for all of non-Windows users supporting id for many years but that’s the way it is and Defrag still runs fine.


Here is the first of the three announces: SteamOS, a Linux-based operating system built around Steam and “designed for the TV and the living room”.

Symbolised by O, check the livingroom for the next announces: [O ] and O+O

Nothing available yet but SteamOS should be available soon as a free download for users and as a freely licensable operating system for manufacturers.

Remote Linux access using X2go

The X2Go project is a fairly efficient way to provide a graphical remote access to a Linux box. It is based on the excellent NoMachine free libraries, which is the technology behind the NX server and the FreeNX project, which seems not developped anymore.

A client will then only need a SSH access to the server to get a full featured graphical remote desktop.

Available for many Linux flavours, MS Windows and Mac OS X, the installation on a Debian client or server is really easy and straightforward, thanks to the packaging effort done by X2Go, and all the relevant information can be found on the wiki of the X2Go project.

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pcount: a simple but fast Linux process counter

While there is many different ways to do it, having a dedicated tool to count how many processes an executable file are currently running was one of my need. And because I wanted a really performant way of doing it, I wrote this tiny tool named pcount.

Here is the full C source code, no specific license attached, the code is really too trivial to claim for anything ^^:

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