Dealing with ssh “hidden” stuff: config file

If you use ssh a lot, you may sometimes feel tired giving same options all the time for the same server.

For example if you have an account ‘alpha’ on a server called ‘tarentula’ you may use the following command:

ssh alpha@tarentula

You may simplify your life: insert the following lines into your .ssh/config:

Host tarentula
    User alpha

Then, you can just type:

ssh tarentula

and you will get logged in ‘tarentula’ with the ‘alpha’ account.

I admit, this is not very impressive. But consider the following lines into your ~/.ssh/config:

Host tarentula
    User alpha
    ForwardX11 yes
    ForwardX11Trusted yes

Host *
    Compression yes

This basically means: for the ‘tarentula’ host given on the command line (this is different than the real host, see below): forward my X display (like if you did a ssh -X tarentula); and for all hosts (including tarentula), enable compression.

Better, if, for some reasons, you are behind a firewall, you can still access to an external server using the following:

Host tarentula
    ProxyCommand corkscrew proxy.company.com 8080 %h %p

Of course, corkscrew should be installed on your machine.

Finally, if you use virtualisation, you may have setup some ssh tunnels in order to access your various virtual machines. But you end up having to type ssh commands such as this one:

ssh -p 22024 beta@10.0.0.10

to enter as ‘beta’ in the 24th virtual machine that 10.0.0.10 is currently running. A config file such as this one:

Host vm24
    HostName 10.0.0.10
    Port 22024
    User beta

will make your life much simpler:

ssh vm24

Choosing the right File System Layout under Linux

As you may probably know, Linux supports various filesystems such as ext2, ext3, ext4, xfs, reiserfs, jfs among others. Few users really consider this part of a system, selecting default options of their distribution’s installer. In this article, I will give some reasons for a better consideration of the file-system and of its layout. I will suggest a top-bottom process for the design of a “smart” layout that remains as stable as possible over time for a given computer usage.

Note: this article has been published in HTML format at www.linuxconfig.org

Déclaration des revenus 2009 et redevance télé

Attention, dans la déclaration préremplie simplifiée envoyée par l’administration fiscale, la case RA portant sur la Redevance Audiovisuelle est décochée même si l’année précédente, vous l’aviez cochée. Ce qui signifie que l’une de vos résidences (principale ou secondaire) est équipée d’un téléviseur. Si comme nous, vous avez décidé de vous passer de télé, il faut évidemment cocher cette case. C’est évident.

Toutefois, si vous déclarez par Internet, on vous offre la possibilité en quelques clics de télédéclarer. Trés pratique, sauf que là encore, par défaut, on suppose que vous avez une télé, SANS VOUS AFFICHER L’OPTION À DÉCOCHER !! Il faut donc demander la modification de la déclaration préremplie afin de cocher cette case.

Vous êtes prévenus.

Le problème du dvorak-fr

La disposition clavier du dvorak-fr distribuée par Xorg dans les distributions Linux a changé il y a peu. En voilà les raisons, et un moyen de revenir à la disposition précédente. Read More »