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Content Tagged with System + Debian
How-To: encrypted partitions over LVM with LUKS
Even though new distros installers tend to support filesystem encryption out of the box, most of the time, it might be interesting to actually understand how it works, mainly when it happens that your system fails to boot :).
Most literature found on the Internet tend to cover how to set up LVM over a partition encrypted with LUKS, this tutorial takes another approach and will explain how to create LUKS encrypted partitions over LVM. The reason for this.... I wanted to have unencrypted partitions :D.
How-To: Remote syslog logging on Debian and Ubuntu
syslogd is the Linux system logging utility that take care of filling up your files in /var/log when it is asked to.
On a standard system, logging is only done on the local drive. But syslog can be configured to receive logging from a remote client, or to send logging to a remote syslog server.
Some of the use cases could be:
- A machine which filesystem goes read-only
- Log replication
this tutorial will explain how to set up both the server, to receive message from a remote client, and the client to emit messages to a syslogd server.
How-To: Set up a LAN gateway with DHCP, Dynamic DNS and iptables on Debian Etch
Linux is a perfect platform to act as a router/gateway.
In this tutorial, I will explain how to set up a Linux box to operate as a network router. The box will provide the following services:
- DHCP server to provide the ip addresses to the machines in the LAN
- DNS server to resolve domain names
- Gateway with IP tables to give access to the Internet.
- Firewall with IP tables.
The resulting machine will have quite a small footprint: about 600M, and except if your network is intensively used, a low spec computer can be recycled to do the job.
As the machine is going to operate as a router/firewall
How-To: copy files over the network and preserve file permissions and informations with ssh and rsync
When copying files over the network, the files informations can be modified.
When using cp, one can avoid this issue by using the -a which will do the copy in archive mode, meaning that it will keep the links, preserve mode, ownership and timestamps and the copy is recursive.
the solution to this over the network is rsync alongside with ssh.
How-To: Intel Wireless 4965 AGN with Ad-Hoc network + WEP
The Intel wireless card 4965 AGN does not work properly on ad-hoc networks since hardy and kernel 2.6.24 or around, network-manager can't get it to use the mode ad-hoc and a standard configuration like:
$ sudo iwconfig wlan0 essid myessid mode ad-hoc channel X key s:mykey13charss
$ sudo dhclient wlan0
will fail to get an ip except a long battle at dhclient'ing around.
I managed to get a process to get things working faster.
eBox Platform
How to fix broken NX user authentication after OpenSSL fix
It looks like OpenSSH Keys generated on Debian derived distros (Ubuntu/Voyage etc.) are REALLY bad. I’m currently rolling out OpenSSL key updates as adviced on http://wiki.debian.org/SSLkeys.
One casualty of this update was my NX server using freenx. It just tells me that I can’t be authenticated. In the log /var/log/freenx.log it shows the following:
– NX SERVER START: -c /usr/lib/nx/nxserver - ORIG_COMMAND=
HELLO NXSERVER - Version 2.1.0-71 OS (GPL)
NX> 105 hello NXCLIENT - Version 2.1.0
NX> 134 Accepted protocol: 2.1.0
NX> 105 SET SHELL_MODE SHELL
NX> 105 SET AUTH_MODE PASSWORD
NX> 105 login
NX> 101 User: shuerlimann
NX> 102 Password:
NX> 404 ERROR: wrong password or login
NX> 999 Bye
This post talks about the NoMachine NX Server, but gave me the necessary clues: http://lists.kde.org/?l=freenx-knx&m=116542288527396&w=2
The magic command for freenx from http://datakeylive.com
on Ubuntu is
sudo rm /var/lib/nxserver/home/.ssh/known_hosts
This is necessary, as the SSH host key has been updated… Well, a more informative error message would’ve been nice, but I’m thankfull to the guys who produce freenx, anyway 
How-To set up a serial console on Debian
This tutorial will go over the steps to go through in order to set up a serial console on Debian Linux.
Debian uses sysvinit to handle the booting process, amongst the different task, and as such, there is a few differences between most of the tutorial that you might find on the internet regarding how to set up a serial console.
A Serial Console becomes handy when running a headless server (i.e no keyboard and screen) or if you cannot connect a a server because of a network issue.
How-To set up a serial console client
In the 2 previous articles, I explained how to set up a serial console on Ubuntu and Debian.
This tutorial will now show how to connect to those serial console using another machine using a software called minicom.
How-To set up a serial console on Ubuntu
This tutorial will go over the steps to go through in order to set up a serial console on Ubuntu Linux.
Unlike most other distros, Ubuntu uses upstart instead of sysvinit and as such, there is a few differences between most of the tutorial that you might find on the internet regarding how to set up a serial console.
A Serial Console becomes handy when running a headless server (i.e no keyboard and screen) or if you cannot connect a a server because of a network issue.
How-To: Import/Export GPG key pair
This tutorial will show how you can export and import a set of GPG keys from one computer to another.
This way, you can sign/encrypt the same way one different computer.
How-To: Customizing SSH client
SSH is great. There is so many thing you can do with it other than just a remote secure shell like X forwarding, port forwarding, authenticate using a private/public key, compress the transmitted stream....
If you have different account that you use on an every day basis, it becomes quickly cumbersome to type those lengthly command lines.
One could work around this by using aliases, the right way would be to use ~/.ssh/config
This tutorial will show some customization examples that should cover most ssh use cases.
How To: booting another Grub from Grub
Chainloading an operating system allows grub to boot an opearating system's boot loader. This is commonly used to boot Windows for instance.
I personnaly use it to be able to have my "production" system's grub on the MBR, and address other distros'grub install on their root partition. The advantage is that kernel updates are real easy to handle. Each testing distro modifying their own grub won't interfere with my main OS bootloader.
This tutorial will explain how to configure grub's menu.lst from the main OS to boot other OSes bootloader through an example.
How-To: email notification upon available package updates with cron-apt
cron-apt is a tool run by a cron job at regular interval that will check for package updates and optionally do some actions.
cron-apt will by default download the packages without installing them.
This tutorial will explain how to set up cron-apt in order to have it send an email to a specified address when updates are ready to be installed.
Lynis - Security and system auditing tool
Lynis is an auditing tool which tests and gathers information from Unix based systems. The audience for this tool are security and system auditors, network specialists and system maintainers.
(...)
Read the rest of Lynis - Security and system auditing tool (188 words)
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Debian: Debian Admin Step By Step Tutorials and articles with screenshots
How-To: Find files on your computer with find
A standard Linux system has an incredible amount of files installed. Looking for a file location can be a painful task to do though a file browser.
Fortunately, there is a nifty command line available by default on any Linux distribution: find.
find can virtually find anything on your computer and comes with a lot of options. This tutorial will introduce a basic use of it and show how you can search your filesystem for file names matching a name pattern.
etckeeper
How to install NVIDIA video card drivers in Debian Lenny
madduck's droppings : /debian/2007.10.03_packaging-with-git
Instalinux - Install Linux the Easy Way
How-to Create a Filesystem within another partition's file
Filesystems are usually created on a partition. When all your hard drive is already partitioned, creating a new partition can become a pain and creating a new filesystem within another filesystem file can save you a lot of hassles.
This tutorial will show the few steps required to have a new filesystem layout set within another filesystem.
Mount a remote file system through ssh Using sshfs
If you want to access a remote file system through ssh you need to install sshfs.sshfs is a filesystem client based on the SSH File Transfer Protocol. Since most SSH servers already support this protocol it is very easy to set up: i.e. on the server side there’s nothing to do. On the client side mounting the file system is as easy as logging into the server with ssh.
- Based on FUSE (the best userspace filesystem framework for linux)
- Multithreading: more than one request can be on it’s way to the server
- Allowing large reads (max 64k)
- Caching directory contents
- sshfs runs entirely in user space. A user using sshfs does not need to deal with the root account of the remote machine. In the case of NFS, Samba etc., the admin of the remote machine has to grant access to those who will be using the services.
Install SSHFS in Debian
#apt-get install fuse-utils sshfs
Next, let’s make sure the following condition is met. In the local system, type (as root)
# modprobe fuse
This will load the FUSE kernel module. Besides SSHFS, the FUSE module allows to do lots of other nifty tricks with file systems, such as the BitTorrent file system, the Bluetooth file system, the User-level versioning file system, the CryptoFS, the Compressed read-only file system and many others.
Now you need to make sure you have installed ssh in your debian server using the following command
# apt-get install ssh
Using SSHFS
SSHFS is very simple to use. The following command
$ sshfs user@host: mountpoint
This will mount the home directory of the user@host account into the local directory named mountpoint. That’s as easy as it gets. (Of course, the mountpoint directory must already exist and have the appropriate permissions).
Example
create the mount point
#mkdir /mnt/remote
#chown [user-name]:[group-name] /mnt/remote/
Add yourself to the fuse group
adduser [your-user] fuse
switch to your user and mount the remote filesystem.
sshfs remote-user@remote.server:/remote/directory /mnt/remote/
If you want to mount a directory other than the home directory, you can specify it after the colon. Actually, a generic sshfs command looks like this:
$ sshfs [user@]host:[dir] mountpoint [options]
Unmount Your Directory
If you want to unmount your directory use the following command
fusermount -u mountpoint
Tags: configuring sshfs debian, install sshfs debian, Mount a remote file system through ssh, Network, sshfs debian, sshfs examples, sshfs featuresconfiguring sshfs debian, install sshfs debian, Mount a remote file system through ssh, Network, sshfs debian, sshfs examples, sshfs features
Debian: Debian Admin Step By Step Tutorials and articles with screenshots
How-To: create a self-signed certificate
This tutorial will explain how to create a self-signed certificate that you will be able to use with apache in order to provide ssl support.
A self signed certificate won't provide as much security guarantees than a CA-signed certificate, but at least you will be able to use encrypted connection to your server.
How-To: Install Ubuntu on LVM partitions.
LVM (Logical Volume Manager) is a great piece of software which allow you to deal with Logical Volumes. Using LVM along with ext3 filesystem, you are allowed to extend the size of your logical drives which is pretty handy when running out of space.
Distributions like Fedora, Suse and Debian have a LVM aware installer. Unfortunately, at the time this article was written, Ubuntu does not offer such settings with the Desktop Install CD.
This article will cover how to create LVM partitions and how-to generate your partitions from this LVM volume.
Frequently Asked Questions - Xfce Wiki - a Wikia wiki
How-To: Managing services with update-rc.d
Linux services can be started, stopped and reloaded with the use of scripts stocked in /etc/init.d/.
However, during start up or when changing runlevel, those scripts are searched in /etc/rcX.d/ where X is the runlevel number.
This tutorial will explain how one can activate, deactivate or modify a service start up.