Archive

Archives pour 01/2024

How to resize a VirtualBox 4+ hard disk (.vdi), the easy way [quick tip]

13/01/2024 Comments off

Source: WebUpd8.org

VirtualBox 4.0 got a very cool new feature that allows you to easily resize a hard disk in just a few seconds. Previously, you had to install Gparted to do this and the procedure was quite slow.

In VirtualBox 4.0+ (see how to install VirtualBox 4.0.x in Ubuntu), to resize a VirtualBox hard disk image (.VDI) firstly locate the folder where the .vdi you want to resize is located – this should be under ~/VirtualBox VMs or ~/.VirtualBox/HardDisks. Then open a terminal, navigate to that folder (« cd /FOLDER/PATH ») and run the following command to resize the .VDI:

VBoxManage modifyhd YOUR_HARD_DISK.vdi --resize SIZE_IN_MB
Where YOUR_HARD_DISK.vdi is the VirtualBox hard disk you want to resize and SIZE_IN_MB is the new virtual hard disk size, in megabytes. For example, the following command will resize the VirtualBox hard disk called « natty.vdi » to 12000 megabytes:
VBoxManage modifyhd natty.vdi --resize 12000
That’s it! The process takes just a few seconds and you should now have a resized VirtualBox hard disk.

 

Tree en une ligne de commande (sed)

13/01/2024 Comments off

Source: didier.misson.net

Mais que fait cette commande ?

Il suffit d’essayer en ligne de commande…

Non, ce n’est pas risqué.

ls -R | grep ":$" | sed -e 's/:$//' -e 's/[^-][^\/]*\//--/g' -e 's/^/ /' -e 's/-/|/'

Cette commande liste vos dossiers en arborescence, sous forme d’un arbre.

C’est plutôt pour le fun, et pour utiliser SED, car on ne va pas retaper cette longue commande à chaque fois !

Voyez donc ce billet comme un exercice, un exemple de ce qu’on peut faire en ligne de commande avec SED, et pas comme un « truc et astuce ».

J’ai ensuite voulu comprendre comment cette commande fonctionnait.

On y retrouve des commandes assez classiques en Linux : ls, grep et sed.

Lire la suite…

Categories: Système Tags: ,

Changer le mot de passe perdu de Webmin

12/01/2024 Comments off

Un jour vous pouvez resté bloqué par un mot de passe perdu pour accéder à Webmin et vous auriez besoin d’un moyen de le changer.

Voici comment: pour commencer, connectez-vous à votre système en ssh.Vous devez trouver où Webmin est installé et donc le chemin que le script utilisera pour réinitialiser le mot de passe. Lire la suite…

Forcer logrotate à créer une nouvelle version d’un fichier de log

11/01/2024 Comments off

Récemment, je me suis aperçu que mon dernier fichier /var/log/auth.log n’avait pas été renouvelé depuis le 17/04/2011… Evidemment, ça n’aide pas à analyser sereinement les fichiers de logs, vu la taille que ça génère: 105306586 c’est-à-dire plus de 100Mo !

Je voulais conserver 26 semaines de logs pour analyser les tentatives d’intrusion et calculer leur évolution au fur et à mesure que je renforçais la protection de mon serveur.

Tout simple:

  • créer un fichier séparé pour auth.log qu’on appelle /etc/logrotate.d/auth:

/var/log/auth.log

{
        rotate 26
        weekly
        missingok
        notifempty
        compress
        delaycompress
        sharedscripts
        postrotate
                reload rsyslog >/dev/null 2>&1 || true
        endscript
}

  • retirer la référence à /var/log/auth.log dans /etc/logrotate.d/auth
  • redémarrer le service rsyslog:
/etc/init.d/rsyslog restart

Lire la suite…

Monitor Network Connections in Mac OS X for Free with Private Eye

11/01/2024 Comments off

Source: OSXdaily

Private Eye is a free real-time network monitor app for Mac OS X that is extremely easy to use. Upon launching the app, you’ll start to see all open network connections by application and process, and you can then filter connections by app, monitor all open connections, or watch only incoming or outgoing transfer.

private-eye-network-connection-monitor-mac

Connections are reported by application, the time of the connection, and arguably the most useful, the IP address that is being connected to by the app, making it easy to see socket and routing data, letting you know exactly what app is communicating with what server or IP address, for both local and broader internet networks. If you have any interest in networking, privacy, security, or you just want to keep an eye on what apps are connecting to the internet and to where, you should download this app, but it’s also an amazingly useful tool for troubleshooting network problems and figuring out what is using the network.

 

Download and install Private Eye by putting it into your /Applications/ folder, then open PrivateEye to get started. The list of open network connections is easy to read, you’ll see a time stamp of the connection, the application name, and where the connection is going to by IP (or coming from, as determined by the arrow pointing left for in, or right for out).

private-eye-connections

Using the left side menu you can quickly break down connections to see them all, only show incoming transfers, outgoing connections, or display connections by specific application only. Apps are easy to identify in this list, as are daemons running in the background (like PubSubAgent), and command line processes belonging to the user are also visible (ssh, for example).

This is a simple yet powerful tool without the complexity or the learning curves related to compiling and using the command line tools lsof, watch, open_ports, or wireshark, and is therefore highly recommended for anyone who is interested in seeing this kind of information, whether it’s out of general curiosity, or to help troubleshoot and diagnose specific network activities.