AirV's Blog

Serveur Ubuntu

Zentyal propose une solution de serveur Ubuntu offrant une palette impressionnante de services :

• DHPCP, DNS, WEB , FTP…
• LDAP, Calendrier, Partage de fichiers, Backup…
• Messsagerie, VoIP…
• Firewall, VPN…

Ndiswrapper

How to Install a Wireless Card in Linux Using Windows Drivers

From HowToGeek.com :

Linux has come a long way with hardware support, but if you have a wireless card that still does not have native Linux drivers you might be able to get the card working with a Windows driver and ndiswrapper.

Using a Windows driver inside of Linux may also give you faster transfer rates or better encryption support depending on your wireless card.

If your wireless card is working, it is not recommended to install the Windows driver just for fun because it could cause a conflict with the native Linux driver.

Download Wireless Card Driver

The first thing you need to do is figure out what wireless card you have. There are a couple ways to do this and some involve finding the device chipset and others involve scouring through system logs.

The easiest method is to just look at the device itself, if you have an external wireless card, or search your manufactures website for what wireless card came with your computer, if you have an internal wireless card.

Once you know what wireless adapter you are trying to install, go to the manufacturer’s website to download the Windows drivers for the device.

If at all possible, you should try to download the 32-bit Windows XP drivers in .zip format rather than .exe. If you don’t have an option, select the latest Windows driver that your manufacturer provides.

Extract Wireless Driver

To extract the files, browse to the .exe or .zip file, right click on it, and select open with archive manager.

Note: Although archive manager can extract both .exe and .zip files, sometimes the files within the .exe may not work with ndiswrapper.

Click extract at the top and copy all the files to an easy to find location.

Install Ndiswrapper

Ndiswrapper is the tool that allows Linux to use Windows drivers for wireless card support.

To install it in Ubuntu go to the Software Center and search for ndisgtk.

Note: Linux Mint comes with ndiswrapper installed.

Install Windows Driver

Now that you have your wireless driver extracted and ndiswrapper installed, open Windows Wireless Drivers from the System -> Administration menu.

In the window that opens, click on install new driver and browse to where you extracted the driver.

Sometimes the .inf files will be in sub-folders inside the driver so you may need to dig around to locate the right file to use.

After you select the .inf file for your wireless card click install. It will take a couple minutes to install the driver so be patient while it works.

After the driver is installed the main window will indicate if you selected the right .inf file by telling you if the hardware is present or not. If you selected the wrong driver the first time you can try installing a different .inf file that was extracted from the driver.

If none of the .inf files work you may want to try the driver for the same card for a different version of Windows (e.g. XP, Vista, 7).

After you get the right driver installed click configure network to open Ubuntu network connections and connect to your wireless network.

If you are still having trouble you may want to check out the ndiswrapper wiki to see if others have had success with the wireless card.

Logical Volume Ubuntu

From HowToGeek :

In our previous article we told you what LVM is and what you may want to use it for, and today we are going to walk you through some of the key management tools of LVM so you will be confident when setting up or expanding your installation.

As stated before, LVM is a abstraction layer between your operating system and physical hard drives. What that means is your physical hard drives and partitions are no longer tied to the hard drives and partitions they reside on. Rather, the hard drives and partitions that your operating system sees can be any number of separate hard drives pooled together or in a software RAID.

To manage LVM there are GUI tools available but to really understand what is happening with your LVM configuration it is probably best to know what the command line tools are. This will be especially useful if you are managing LVM on a server or distribution that does not offer GUI tools.

Most of the commands in LVM are very similar to each other. Each valid command is preceded by one of the following:

• Physical Volume = pv
• Volume Group = vg
• Logical Volume = lv

The physical volume commands are for adding or removing hard drives in volume groups. Volume group commands are for changing what abstracted set of physical partitions are presented to your operating in logical volumes. Logical volume commands will present the volume groups as partitions so that your operating system can use the designated space.

Downloadable LVM Cheat Sheet

To help you understand what commands are available for each prefix we made a LVM cheat sheet. We will cover some of the commands in this article, but there is still a lot you can do that won’t be covered here.

All commands on this list will need to be run as root because you are changing system wide settings that will affect the entire machine.

(Click on the thumbnail for a full size image)

How to View Current LVM Information

The first thing you may need to do is check how your LVM is set up. The s and displaycommands work with physical volumes (pv), volume groups (vg), and logical volumes (lv) so it is a good place to start when trying to figure out the current settings.

The display command will format the information so it’s easier to understand than the scommand. For each command you will see the name and path of the pv/vg and it should also give information about free and used space.

The most important information will be the PV name and VG name. With those two pieces of information we can continue working on the LVM setup.

Creating a Logical Volume

Logical volumes are the partitions that your operating system uses in LVM. To create a logical volume we first need to have a physical volume and volume group. Here are all of the steps necessary to create a new logical volume.

Create physical volume

We will start from scratch with a brand new hard drive with no partitions or information on it. Start by finding which disk you will be working with. (/dev/sda, sdb, etc.)

Note: Remember all of the commands will need to be run as root or by adding ’sudo’ to the beginning of the command.

fdisk -l

If your hard drive has never been formatted or partitioned before you will probably see something like this in the fdisk output. This is completely fine because we are going to create the needed partitions in the next steps.

Our new disk is located at /dev/sdb so lets use fdisk to create a new partition on the drive.

There are a plethora of tools that can create a new partition with a GUI, including Gparted, but since we have the terminal open already, we will use fdisk to create the needed partition.

From a terminal type the following commands:

fdisk /dev/sdb

This will put you in a special fdisk prompt.

Enter the commands in the order given to create a new primary partition that uses 100% of the new hard drive and is ready for LVM. If you need to change the partition size or want multiple partions I suggest using GParted or reading about fdisk on your own.

Warning: The following steps will format your hard drive. Make sure you don’t have any information on this hard drive before following these steps.

• n = create new partition
• p = creates primary partition
• 1 = makes partition the first on the disk

Push enter twice to accept the default first cylinder and last cylinder.

To prepare the partition to be used by LVM use the following two commands.

• t = change partition type
• 8e = changes to LVM partition type

Verify and write the information to the hard drive.

• p = view partition setup so we can review before writing changes to disk
• w = write changes to disk

After those commands, the fdisk prompt should exit and you will be back to the bash prompt of your terminal.

Enter pvcreate /dev/sdb1 to create a LVM physical volume on the partition we just created.

You may be asking why we didn’t format the partition with a file system but don’t worry, that step comes later.

Create volume Group

Now that we have a partition designated and physical volume created we need to create the volume group. Luckily this only takes one command.

vgcreate vgpool /dev/sdb1

Vgpool is the name of the new volume group we created. You can name it whatever you’d like but it is recommended to put vg at the front of the label so if you reference it later you will know it is a volume group.

Create logical volume

To create the logical volume that LVM will use:

lvcreate -L 3G -n lvstuff vgpool

The -L command designates the size of the logical volume, in this case 3 GB, and the -n command names the volume. Vgpool is referenced so that the lvcreate command knows what volume to get the space from.

Format and Mount the Logical Volume

One final step is to format the new logical volume with a file system. If you want help choosing a Linux file system, read our how to that can help you choose the best file system for your needs.

mkfs -t ext3 /dev/vgpool/lvstuff

Create a mount point and then mount the volume somewhere you can use it.

mkdir /mnt/stuff
mount -t ext3 /dev/vgpool/lvstuff /mnt/stuff

Resizing a Logical Volume

One of the benefits of logical volumes is you can make your shares physically bigger or smaller without having to move everything to a bigger hard drive. Instead, you can add a new hard drive and extend your volume group on the fly. Or if you have a hard drive that isn’t used you can remove it from the volume group to shrink your logical volume.

There are three basic tools for making physical volumes, volume groups, and logical volumes bigger or smaller.

Note: Each of these commands will need to be preceded by pv, vg, or lv depending on what you are working with.

• resize – can shrink or expand physical volumes and logical volumes but not volume groups
• extend – can make volume groups and logical volumes bigger but not smaller
• reduce – can make volume groups and logical volumes smaller but not bigger

Let’s walk through an example of how to add a new hard drive to the logical volume “lvstuff” we just created.

Install and Format new Hard Drive

To install a new hard drive follow the steps above to create a new partition and add change it’s partition type to LVM (8e). Then use pvcreate to create a physical volume that LVM can recognize.

Add New Hard Drive to Volume Group

To add the new hard drive to a volume group you just need to know what your new partition is, /dev/sdc1 in our case, and the name of the volume group you want to add it to.

This will add the new physical volume to the existing volume group.

vgextend vgpool /dev/sdc1

Extend Logical Volume

To resize the logical volume we need to say how much we want to extend by size instead of by device. In our example we just added a 8 GB hard drive to our 3 GB vgpool. To make that space usable we can use lvextend or lvresize.

lvextend -L8G /dev/vgpool/lvstuff

While this command will work you will see that it will actually resize our logical volume to 8 GB instead of adding 8 GB to the existing volume like we wanted. To add the last 3 available gigabytes you need to use the following command.

lvextend -L+3G /dev/vgpool/lvstuff

Now our logical volume is 11 GB in size.

Extend File System

The logical volume is 11 GB but the file system on that volume is still only 3 GB. To make the file system use the entire 11 GB available you have to use the command resize2fs. Just point resize2fs to the 11 GB logical volume and it will do the magic for you.

resize2fs /dev/vgpool/lvstuff

Note: If you are using a different file system besides ext3/4 please see your file systems resize tools.

Shrink Logical Volume

If you wanted to remove a hard drive from a volume group you would need to follow the above steps in reverse order and use lvreduce and vgreduce instead.

1. resize file system (make sure to move files to a safe area of the hard drive before resizing)
2. reduce logical volume (instead of + to extend you can also use – to reduce by size)
3. remove hard drive from volume group with vgreduce

Backing up a Logical Volume

Snapshots is a feature that some newer advanced file systems come with but ext3/4 lacks the ability to do snapshots on the fly. One of the coolest things about LVM snapshots is your file system is never taken offline and you can have as many as you want without taking up extra hard drive space.

When LVM takes a snapshot, a picture is taken of exactly how the logical volume looks and that picture can be used to make a copy on a different hard drive. While a copy is being made, any new information that needs to be added to the logical volume is written to the disk just like normal, but changes are tracked so that the original picture never gets destroyed.

To create a snapshot we need to create a new logical volume with enough free space to hold any new information that will be written to the logical volume while we make a backup. If the drive is not actively being written to you can use a very small amount of storage. Once we are done with our backup we just remove the temporary logical volume and the original logical volume will continue on as normal.

Create New Snapshot

To create a snapshot of lvstuff use the lvcreate command like before but use the -s flag.

lvcreate -L512M -s -n lvstuffbackup /dev/vgpool/lvstuff

Here we created a logical volume with only 512 MB because the drive isn’t being actively used. The 512 MB will store any new writes while we make our backup.

Mount New Snapshot

Just like before we need to create a mount point and mount the new snapshot so we can copy files from it.

mkdir /mnt/lvstuffbackup
mount /dev/vgpool/lvstuffbackup /mnt/lvstuffbackup

Copy Snapshot and Delete Logical Volume

All you have left to do is copy all of the files from /mnt/lvstuffbackup/ to an external hard drive or tar it up so it is all in one file.

Note: tar -c will create an archive and -f will say the location and file name of the archive. For help with the tar command use man tar in the terminal.

tar -cf /home/rothgar/Backup/lvstuff-ss /mnt/lvstuffbackup/

Remember that while the backup is taking place all of the files that would be written to lvstuff are being tracked in the temporary logical volume we created earlier. Make sure you have enough free space while the backup is happening.

Once the backup finishes, unmount the volume and remove the temporary snapshot.

umount /mnt/lvstuffbackup
lvremove /dev/vgpool/lvstuffbackup/

Deleting a Logical Volume

To delete a logical volume you need to first make sure the volume is unmounted, and then you can use lvremove to delete it. You can also remove a volume group once the logical volumes have been deleted and a physical volume after the volume group is deleted.

Here are all the commands using the volumes and groups we’ve created.

umount /mnt/lvstuff
lvremove /dev/vgpool/lvstuff
vgremove vgpool
pvremove /dev/sdb1 /dev/sdc1

That should cover most of what you need to know to use LVM. If you’ve got some experience on the topic, be sure to share your wisdom in the comments

WakeOnLan

Sous Windows

• Airytec Switch Off permet d’éteindre, de redémarrer ou de mettre en hibernation un ordinateur de manière automatique ou à distance à partir d’un autre ordinateur ou d’un téléphone mobile. Le logiciel peut aussi déconnecter les connexions dial-up (connexions à un réseau par une ligne téléphonique) et VPN (réseau privé virtuel). L’opération peut être programmée à partir de n’importe quel ordinateur ou téléphoné doté d’un navigateur Web.

Sous linux

From Doc-Ubuntu-fr.org

« Le Wake-on-LAN ou mise en marche du PC depuis le réseau est une technologie développée par AMD et IBM, permettant à un ordinateur mis en veille d’être démarré à distance par l’envoi d’un « magic-packet » sur la carte réseau supportant le Wake-on-LAN.

Plus techniquement, le réveil est déclenché quand la carte ethernet de l’ordinateur reçoit un « magic packet » qui est une trame de données ethernet contenant les octets FF FF FF FF FF FF suivis de seize répétitions de l’adresse MAC de la cible, puis d’un mot de passe (si nécessaire) de quatre ou six octets. »

Derrière une Freebox il suffit de cocher la case Proxy WOL (Wake On Lan) depuis la console de gestion. Si l’on ajoute la redirection de ports (9) cela ne fonctionnera pas…

Un script en ligne pour allumer son PC.

NB : ne pas oublier de préciser la mac-address

En ligne de commande :

wakeonlan -i IP MACADRESS

Sécuriser Apache2 avec SSL

From Doc.Ubuntu-fr.org :

• Pour que le protocole SSL puisse fonctionner avec le Serveur HTTP Apache2, il faut activer le module ssl avec la commande :

sudo a2enmod ssl

• puis recharger la configuration d’Apache2 faîtes :

sudo service apache2 force-reload

Utilitaire disque sous linux

From HowToGeek.com :

Knowing how to check the condition of your hard disk is useful to determine when to replace your hard disk. In today’s article, we will show you some Linux disk utilities to diagnose the health of your hard disk.

Image by Scoobay

S.M.A.R.T System

Most modern ATA and SCSI hard disks have a Self-Monitoring, Analysis, and Reporting Technology (SMART) system. SMART hard disks internally monitor their own health and performance.

The SMART tool assesses the condition of your hard disk based on: the throughput of the hard disk, the seek errors rate of the magnetic heads, and other attributes that your hard disk manufacturer built into their hard disk.

Most implementations of SMART systems allow users to perform self-tests to monitor the performance and reliability of their hard disks. The simplest way to perform a SMART system test with Ubuntu is using the ‘Disk Utility’ under the ‘System’ > ‘Administration’ menu.

The disk utility lets you see the model, serial number, firmware, and the overall health assessment of the hard disk, as well as whether a SMART system is enabled on the hard disk.

The ‘SMART data’ button lets you see the SMART features of your hard disk.

The ‘Run Self-test’ button lets you initiate a short,extended, or a conveyance self-test on the hard disk.

When you execute these tests, you’ll see a progress meter, letting you see how far through the test is and what the estimated time of completion is.

The ‘Attributed section’ lets you see the errors and self-test information.

File System Check

There some other tools, beside the Disk Utility GUI, that we can use to diagnose the health of our hard disk. The File System Check (FSCK), that only comes as a command line tool, is one of the tools that we often use to check the condition of our hard disk.

You can use the ‘Check Filesystem’ feature of the ‘Disk Utility’ to perform the same check,if you are not a command line geek like us.

Of course, there are some situations where we have to use the command line tool to check our file system. For example when we are using a headless system, when our Linux box fails to boot, or when we simply want to show off our command line Kungfu skills to our friends.

At first, the FSCK command line tool looks like something that only a computer geek can handle; But you will find that FSCK is a very easy tool to use. There is one thing to note before you run FSCK; You need to unmount the file system using the ‘umount’ command. Fixing a mounted file system with FSCK could end up creating more damage than the original problem.

sudo umount /dev/sdb

The FSCK command is pretty straightforward:

sudo fsck -t ext4 /dev/sdb

This command checks an ext4 file system (/dev/sdb) for inconsistencies. You should replace /dev/sdb with your own partition. You can run the ‘fdisk’ command to find out your system partitions:

sudo fdisk -l

Scheduled File System Checks

If you’re using Ubuntu, you will notice that Ubuntu runs an FSCK session when you boot your system from time to time. If you find this scheduled check annoying, you can re-schedule the scan using the ‘tune2fs’ command. Here’s how it typically looks like:

The mount count parameter tells us that Ubuntu scans our hard disk after 33 disk mounts.

We can configure the mount count using the ‘-c’ option:

sudo tune2fs -c 35 /dev/sda1

This command will re-configure Ubuntu to scan our hard disk after 35 hard disk mounts when the system boots.

Note: change ‘/dev/sda1/’ with your own partition

Bad Blocks

A bad sector is a sector on a computer’s disk drive that cannot be used due to permanent damage (or an OS inability to successfully access it), such as physical damage to the disk surface.

There are two ways to detect bad sectors in Linux: you can use the Disk Utility GUI, or if you are a command line geek like us, you can use the badblocks command to check your hard disk for bad sectors:

sudo badblocks -v /dev/sdb1

Badblock will give us the number of bad sectors in our hard disk.


zainul@zainul-laptop:~$ sudo badblocks -v /dev/sdb1
Checking blocks 0 to 97683200
Checking for bad blocks (read-only test): 3134528 done, 3:27 elapsed
3134560 done, 8:33 elapsed
3134561 done, 10:15 elapsed
3134562 done, 11:57 elapsed
3134563 done, 13:39 elapsed
done
Pass completed, 5 bad blocks found.


You have two options when you see bad blocks. You can either look for a new hard disk, or mark these bad blocks as unusable hard disk sectors. This involves two steps:

First we have to write the location of the bad sectors into a flat file.

sudo badblocks /dev/sdb > /home/zainul/bad-blocks

After that, we need to feed the flat file into the FSCK command to mark these bad sectors as ‘unusable’ sectors.

sudo fsck -l bad-blocks /dev/sdb

FSCK, Badblocks, and Disk Utility are some of the disk utilities that we often use to scan our hard disks. Do share with the other fellow readers if you know other Linux disk utilities to scan hard disks.

Comment réinstaller Grub2

From Doc-Ubuntu.org :

• Amorcez votre ordinateur sur un CD Live
• Monter la partition contenant votre grub2

menu Raccourcis et sélectionnez la partition à monter dans la liste des partitions existantes

• Vérifiez que vos OS sont listés

sudo os-prober

• Réinstallez grub
  

sudo grub-install –root-directory=/media/MaPartionGrub2 /dev/sda

Autre solution le chroot

Backup Ubuntu

From Freshmeat.net :

« …Arkeia Network Backup Enterprise Edition for Ubuntu is a completely free version of the Arkeia Network Backup software specifically for Ubuntu servers. It allows an administrator to backup and restore files via a powerful easy to use Web UI. This edition has the option to backup to a 250 GB VTL or tape drive. All Arkeia products support any tape drive that is compatible with the Linux st driver. This edition allows you to backup Windows desktops, Mac desktops, Linux servers, FreeBSD servers, and more… »

Site officiel

A tester.

Packages installés

From Ubuntu.org :

Sauvegarde

• Récupérez la liste des paquets installés sur le système :

   # dpkg --get-selections > liste-des-paquets

• sauvegardez le fichier /etc/apt/sources.list

Restauration

• Récupérez votre fichier « liste-des-paquets » puis :

   # sudo apt-get update
   # sudo dpkg --set-selections < liste-des-paquets
   # sudo apt-get -u dselect-upgrade

Script post-installation

• voir le script de post-installation de . Ernst
• script d’installation de packages

Post-installation

• AdobeAir
• Dropbox
• GoogleChrome
• Ubuntu TweakVoir le post migration Ubuntu 10.4

PAC Manager

From Davidtv :

« …PAC is a Perl/GTK Gnome replacement for SecureCRT/Putty/etc… It provides a GUI to configure SSH/Telnet connections: users, passwords, EXPECT regular expressions, macros, etc. You like ‘SSHMenu’? If so, you must check this tool. Just let me know how do you feel about it!… »

Testé et approuvé 🙂

Dépôt :

• Add to your /etc/sources.list file

deb http://archive.getdeb.net/ubuntu lucid-getdeb apps

• then « update »
• and finally install « pac ».