Tips for Linux Explorers

[Bruno]

CHANGING HOSTNAME IN D*** SMALL LINUX HD INSTALLOpen ( as root ) the file /etc/init.d/knoppix-autoconfig and find the line:

hostname box

. . change the word "box" to the hostname you desire.Next open the /etc/hosts file and change the word "box" in the line:

127.0.0.1 box localhost

Also open the /etc/hostname and change "box"Then reboot and be happy . . . BrunoPS: For changing the hostname in other distros see Here

[Bruno]

WHAT DAY WAS YESTERDAY ?Ever lose track of time, puzzled about what day it is, or are just curious what day your birthday will be in 2022 ?Here are a few nice commands to keep you up to date:

$ cal

Shows you the current month

$ cal -3

The same calendar with 3 month display

$ cal 9 1950

The calender for September 1950

$ cal -y

The calendar for full year

$ cal -y 1950

The calendar of the year 1950

$ date

Current time and date

$ date -d sun

The date for next Sunday

$ date --date='Jan 1 2008' +%A

New Years day 2008

$ TZ=':America/New_York' date

Current time in NY

$ time <command>

Measure how long a command takes ( + cpu usage )

$ uptime

Uptime since last boot

$ hwclock --show

Shows time and date the BIOS hardware clock is set

$ w

The users, when they logged in, and what they are doingThese are just a few of the very nice commands Linux gives you for "free" . . . . . If you want to know what day this text was written, look at the top of this post. <g> Bruno

[Bruno]

LDCONFIG, ( Where are the Libs ? )Sometimes when you install a program from source it can complain that a certain library is missing . . . and still you know that the lib it is complaining about is actually installed on your system. But most likely it is not on the default place ( /usr/lib ) where the program looks for the lib.There is a file on your system where all the paths to the libraries are mentioned: the /etc/ld.so.conf file. Here is an example of the /etc/ld.so.conf file on Slackware:

/usr/local/lib/usr/X11R6/lib/usr/i486-slackware-linux/lib/usr/lib/opt/kde/lib

So, what's the solution ? 1). First locate the lib the program is complaining about, maybe it is in /usr/lib/qt/lib or in /usr/include or any other odd location.2). Next add the path to that lib in the /etc/ld.so.conf file. So, for our example the /etc/ld.so.conf file would look like:

/usr/local/lib/usr/X11R6/lib/usr/i486-slackware-linux/lib/usr/lib/opt/kde/lib/usr/lib/qt/lib /usr/include

3). Finally to let the system know that you updated the /etc/ld.so.conf file and make it use the new values give the command:

# ldconfig

Now you can run the program that was complaining when we started this Tip and you will see that this time it will find the library . . . . . have fun ! Bruno

[Bruno]

MBR / Hard Disk LayoutThe MBR is the very first part of your hard disk stores the boot loader and the partition table.Basically it comes to this:The MBR is 512 bytes . . the first 446 bytes are for the boot loader, and the bytes from 446 to 512 are for the partition table. If you delete the full 512 bytes you will not only delete the boot loader but you will have lost the partition table as well . . . so:If you back up the MBR to floppy you do:

# dd if=/dev/hda of=/dev/fd0/boot.mbr bs=512 count=1

Once the disk is clean and you want to restore:

# dd if=/dev/fd0/boot.mbr of=/dev/hda bs=512 count=1

This will restore the original partition table and the boot loader you had in the MBR.Now, if you only want to clear the boot loader part ( and keep the partition table intact ) you do:

# dd if=/dev/zero of=/dev/hda bs=446 count=1

Then you can either restore your favorite Linux boot loader , see Grub or Lilo info ( sure you will need a rescue CD / bootCD first to boot or chroot the Linux partition ) or you can restore your Windows boot loader ( see Here ) Technical info on recovering a deleted partition table: http://www.linuxdocs.org/HOWTOs/ ( warning: this is not easy ! ):'( Bruno

[Bruno]

INSTALLING MACROMEDIA FLASH PLAYEROne of the first browser plugins you probably will want to install would be the flash plugin. ( If your distro did not do it by default during the install of the OS )The way to install it is a little bit different then the usual packages, that is why I will give a brief how-to.Go to: http://www.macromedia.com/shockwave/downlo...rsion=Netscape4Press the "Option 1: tar.gz" button and download the "install_flash_player_9_linux.tar.gz" to your /home directory.Next:

$ tar -xvzf install_flash_player_9_linux.tar.gz$ su< password ># cd install_flash_player_9_linux# cp flashplayer.xpt /usr/lib/mozilla/plugins/# cp libflashplayer.so /usr/lib/mozilla/plugins/

NOTE: In SUSE the /usr/lib/mozilla/plugins/ directory is in /opt/mozilla/plugins/ . . in SUSE 10.2 it is /usr/lib/firefox/plugins/ !!In Ubuntu you use the /usr/lib/mozilla-firefox/plugins/ directory.Then check if the 2 files "flashplayer.xpt" and "libflashplayer.so" are indeed in the correct directory:

# ls -al /usr/lib/mozilla/plugins/

And finally open your browser and type in the address bar: "about:plugins" to see if the browser indeed lists them. If they are there you can sit back and enjoy surfing. Bruno

[Bruno]

EASY CONFIG FILE BACKUPHere is a neat trick, if you want to edit a file, and just to be sure you want to make a backup of the original before you start editing the file, there is an easy command. Let's say you want to edit the xorg.conf file ( and you know that is a critical job ) here is the command:

# cp /etc/X11/xorg.conf{,-BACKUP}

This will create a file called xorg.conf-BACKUP in the same directory as the original . . . so if disaster strikes you simply restore the backup with:

# cp /etc/X11/xorg.conf-BACKUP /etc/X11/xorg.conf

And all is fine again. Bruno

[Bruno]

UMASK( Advanced permissions )Before you read this Tip be sure to check out File Permissions and Changing File PermissionsUmask is the number subtracted from the standard permissions when creating a file. Example: each new file is by default created with 666, so when umask is set to 022, the result is that the permissions will be 666 - 022 = 644 ( meaning read-write for the owner and only read for the group and all others.Most of the time umask will already be set by your distro to 022 but you can change it if you like. You can see what umask value is set with:

$ umask

You can set umask to another value like this:

$ umask 066

That value will then stay until you log out and then return to its default value. If you want the alternative value to be permanent put "umask 066" in your ~/.bash_profile or/and for root in /root/.bash_profile.If you like your install to be more secure you might set the umask value of root to umask=066 in /root/.bash_profile so every file root makes has disabled read and write permissions for others than root. BrunoMore info: http://www.linuxsecurity.com/content/view/117255/

[Bruno]

STORE and SYNC MANDRIVA UPDATES LOCALLY( For applying on several installs/computers )Imagine you want to mirror the Mandriva updates ftp directory locally so you can use it to update several installs ( or even just one ). Here is how you do it.Preparation: ( Assuming that you have a backup partition on hdaX where "X" represents the number of the partition )

# mkdir /mnt/hdaX# mount /dev/hdaX /mnt/hdaX# mkdir /mnt/hdaX/MyUpdates

Now the real action, this is for the MDV 2006 updates: ( command is ONE line ! )

# rsync -P -v -r --delete ftp.nluug.nl::Mandrakelinux/official/updates/2006.0/main_updates/ /mnt/hdaX/MyUpdates

This will download the updates . . . . I used "rsync" and not "wget" because with rsync you can use the exact same command next time ( every day if you want ) to "update" the updates, it will then compare your directory with the remote one and only download the changes, rsync is pure magic !!Once all the updates are downloaded you add the "new source" to the urpmi.cfg with:

# urpmi.addmedia update_source file://mnt/hdaX/MyUpdates/ with media_info/hdlist.cz

Finally, go to the package manager in the Mandrake Control Center, section rpm-sources and tick the "updates" box for the update_source.Now every time you do the updates in the MCC it will look in /mnt/hdaX/MyUpdates if there are new updates available and install them if needed. ( sure, you have to rsync the /mnt/hdaX/MyUpdates first with the command printed above. )Have fun ! ( and make sure that during all this time the /mnt/hdaX is mounted !! ) BrunoPS: You can also burn the updates to CD: "mkisofs -R -o Update.iso /mnt/hdaX/MyUpdates" will make an ISO file which you can use to make the CD. ( See also the second part Here on how to use the UpdateCD )

[Bruno]

LOCAL MAIL IN MANDRIVAIf you want cron-messages to root and other local mail to arrive in Evolution you will have to configure a few things in Mandiva.( For Kmail or Thunderbird see note at the end )First install postfix ( in the MCC or simply "urpmi postfix" )Next edit the "/etc/postfix/aliases" file. Here is the part to look for:

# CHANGE THIS LINE to an account of a HUMANroot: bruno

Then check what the hostname is:

# hostname

( On my system it told me the hostname was "jupiter" )And with that info edit the "/etc/postfix/main.cf" file, this part:

myhostname = jupiter.localdomainmynetworks_style = hostinet_interface = localhost

Next open a terminal and give the command to restart the postfix service:

# service postfix restart

Now we will send a test mail, type:

# mail root

You will see "Subject:", now type "testing" as the Subject, hit <Enter> and the cursor will wait on the next line for your input, so type "The Test" as the body of the e-mail and hit <Enter> again, next do <Ctrl+D> on the new line, this will close the mail and send it. ( you will see EOT printed and get your prompt back )Next we will add a new account to Evolution:- The email address is: bruno@jupiter.localdomain- On the Receiving Mail tab:Server Type: Local DeliveryPath: /var/spool/mail/bruno- On the Sending Mail tab:Server type: SendmailThat's all, now you can "send and receive" and you will see the test mail we sent above arrive in your in-box.NOTE: For Kmail the settings are basically the same, you can use "FCNTL" or "None" as locking mode.In Thunderbird the account type is "Movemail" Have FUN sending mail to yourself, to root or to other users on your computer. BrunoExtra, some examples of sending mail in one command:

# cat /var/log/boot.log | mail -s "BootLog" root

Or:

# tail -n 40 /var/log/messages | mail -s "Log Messages" root

[Bruno]

WINDOWS TOOLS: BURNING ISOsJulia ( aka teacher ) sent us the following Tip:A couple of our penguins have recommended some Windows-based tools that can make the difference between a tough install and an easy install. Liz “zlim” recommended a program called Micro CD Burner You can download it here. This program works in windows and allows you to quickly and easily burn an ISO image correctly. You simply click on the “Burn ISO” tab and a new window opens up. Then click on the Drive tab just below the menu and use the drop down to identify your burner. Click the “Burn ISO” link at the top, locate your ISO image and you are on your way. This is a program that you may test or purchase.Arctucus recommends a program called “DeepBurner” Download it here. It has both a free and a professional version. You simply click on “Burn ISO Image" when you open it and you are then in business. Pedro Sanchez sent us to http://burnatonce.com For ISOs you only need to "load iso", click burn and be done. Burnatonce is small (less than 4 MB) and it's free. Bruno

[Bruno]

WINDOWS TOOLS: GPARTED( Sizing an NTFS Partition )Julia ( aka teacher ) sent us the following Tip:If you have an NTFS partition that is being a little troublesome, you might need a program designed to boot from disk that allows you total control over your hard drive to resize or partition your NTFS and other partitions. One tool for partitioning a NTFS partition before installing your program is the Gnu Parted Project Gparted is a small 36 MB ISO-imaged program that you can simply click to download and then burn it with one of the two packages in the tip: WINDOWS TOOLS: BURNING ISOs The first thing you need to do after burning your CD is put it in your CD-ROM drive and make sure your BIOS is set to allow you to boot for CD. When it boots up it will come up to the first screen. Simply press enter to “boot” the computer from the disk. Next you will get a series of screens where it asks for your monitor parameters. You can simply press enter at each screen if you don't know your settings. Most computers are set up for a monitor resolution of 1024x768 as well as a setting of 16 or 24 million colors. Now you will come to a screen with a menu at the top and a graphic showing your hard drive. It might look a little daunting but it really is not. It looks like this: <--click to enlargeThere are two ways to select your drive and partition it. First click on “Edit” and then “Resize” at the top of your screen. <--click to enlargeThe first method is to click on the image of your drive and grab either end of a drive you want to resize by dragging it to the size you want. The second method is to go down below and change the numbers in each of the selection boxes. The “Free Space Preceding” box will move your partition to the right. Set your size in the new size box. The “Free Space Following” box will allow you to set how much space there is after your drive. Keep in mind that as you change the size in one of the boxes it will change the others.One you have finished then you select the type of partition and the File System. You can set it as ext3 if you are looking at any of the distros. Some distros can be set as Reiser but some do not handle that well. If you are partitioning it for Windows you most likely will want FAT32 to make it easy to ready from Linux. If it is for a Windows 95 or earlier, then select FAT16.Once you are done you need to select “Edit” and then “Apply” at the top of your screen.When you close this out you will have a blank screen with a button at the very bottom right corner that looks like a power button. Click on the button to reboot your computer. Don't forget to remove your disk as your computer starts back up or you will find yourself going right back into Gparted. Have fun preparing your drive for Linux. Bruno

[Bruno]

D*** SMALL LINUX from USBSaving Personal Files Since D Small Linux includes a script that makes it easy to install the distro to an USB thumbdrive and make it bootable, there are questions on how to save personal files and downloaded extensions. In this Tip you can read how to save personal files ( doc, mp3, txt, etc. ), and next week we will show how to save the MyDSL extensions you downloaded.Make a new directory in /ramdisk/home/dsl and for the example I will call it "bruno"

$ mkdir  /ramdisk/home/dsl/bruno

Now ALL the files you want to save for the next boot you are going to move to /ramdisk/home/dsl/bruno . . . . only there will they be available at next boot.NOTE: It zips the files at shutdown, so if you have many files in /ramdisk/home/dsl/bruno the shutdown may take longer then usual. BrunoPS: There is a "mount-app" in the right-bottom-corner of the screen where you can "mount" your hda1 ( XP partition ) . . . . you will be able to move files from the XP partition to DSL . . . . but you can not write to the XP partition as long as it is formatted NTFS ( writing to FAT partitions is possible though ! )

[Bruno]

D*** SMALL LINUX from USBSaving downloaded dsl extensionsHere is the how-to "saving downloaded dsl extensions" on a dsl booting from USB-Stick1). First we have to make a directory where you will save the extensions on your USB-Stick. . . so either in windows enter the USB and make a directory called "optional" . . . OR do it the Linux way:Open the ATerminal ( or XTerminal ) and:

$ sudo mount /dev/sda1 /mnt/sda1$ sudo mkdir /mnt/sda1/optional$ sudo umount /mnt/sda1

2). Next get the extensions the "normal" way and save them first to "/ramdisk/home/dsl"3). Mount the sda1 partition:

$ sudo mount /dev/sda1 /mnt/sda1

4). Open Emelfm as root:

$ sudo emelfm

5). Once Emelfm is open you will see in the left panel "/ramdisk/home/dsl" ( where your extensions are temporary ) and in the right panel you have to change to "/mnt/sda1/optional"6). Copy over the files with .dsl extension from the left to the right side ( to "/mnt/sda1/optional" )7). Next time you boot you will find the extensions you saved in the Menu --> MyDSLIf you want to add even more new extensions . . repeat 2 to 6Now you can take your USB-Stick to every computer you can find ( from Iceland to Antarctica ) that boots from USB and you will have your favorite OS + favorite programs booted in seconds.Have fun !! Bruno

[Bruno]

INIT ( Startup Scripts )The boot process of a Linux distro is a complex process, and today we will shed some light on a small part of it: The init-scripts.Let's say you have a program you want to start at boot, depending on the runlevel ( See Runlevels ). Here are two ways to get the job done:1). The first way is you add the command to start your program at the end of the "rc.local" file. Here is a list of the location of that file in the major distros:Fedora: /etc/rc.localSlackware: /etc/rc.d/rc.localSUSE: /etc/init.d/boot.localMandriva: /etc/rc.localPCLos: /etc/rc.local2). Or, if starting the program takes more than one line, make a simple bash-script ( See Bash Script ), make it executable and place the script in the /etc/init.d directory. The next step is to decide what runlevel you want the script to be executed, the runlevels are represented by directories you will find in /etc/rc.d they are numbered rc1.d, to rc6.d ( in Debian and Ubuntu see the "README" in the /etc/rcS.d directory ) . . . . you might want to have a look in one of them:

# ls -al /etc/rc.d/rc5.d

And you will see that all the files in there are actually links and that they start with a code.All these symlinks are starting either with an "S" or with a "K", the "S" is for start, the "K" stands for Kill. Just after the S there is a number, for example 04, this stands for the order in which those scripts are executed in that level.So in a nutshell: if you have a script called "clocksync" place it in /etc/init.d and symlink it with:

# ln -s /etc/init.d/clocksync  /etc/rc.d/rc5.d/S90clocksync

This way you are sure it will start at the end of the bootup in runlevel 5 . . . . . ( make sure the /etc/init.d/clocksync is executable or it will not work ! )If you then discover the "clocksync" program starts too late, you simply remove the link and make a new one with a lower "S" number. BrunoPS: More about the Linux boot process: http://bobcares.com/article18.html

[Bruno]

MAKE ISO from CDSure we all know the command to burn a CD from an ISO with cdrecord:

# cdrecord  dev=/dev/hdc  example.iso

Now we will reverse the process and I will show you 2 different ways how to make an ISO from a CD:

# cat /dev/hdc > example.iso

And

# dd if=/dev/hdc of=example.iso bs=2048 conv=notrunc

Both commands do exactly the same, but the first one might be easier to remember. NOTE: You use the /dev device in both cases and not the place where it is mounted ( /mnt ). Bruno

[Bruno]

SHARING FIREFOX and THUNDERBIRD CONFIG( in Windows and Linux )There are many people dual booting and running Firefox or Thunderbird both in Linux and Windows.To be able to share bookmarks, favorites and mail between the two operating systems seems to be the last step to computer nirvana. Imagine getting mail in Linux and being able to reply to that same mail in Windows . . . . or just having one set of bookmarks between the two OS.Our friend Boilertech found the answer and wrote us this next Tip:

First thing you need is to have a dual boot system set up. I have Windows and Pclinux on mine but this should also work with multiple linux OS's.Next needed is a Fat32 partition (not needed for multi linux OS's). And read write permision. For help making partitions in windows . For making partitions in linux run DiskDrake.This is what my fstab looks like for my fat32 partition.

/dev/hda7 /mnt/Moz_Share vfat umask=0,user,codepage=850,iocharset=iso8859-1,exec 0 0

The part (/mnt/Moz_Share) is the way that I mount that partition. You would need to change this to your preferences. For more information on fstab click here. Then we create a directory to put the shared data in. After you have read/write permision, use the mkdir command to make a folder, or as I did, right click and choose create folder in your file manager. I used my name (just in case there were to be multiple users). So my directory tree looks like this

/mnt/Moz_Share/Mike

Under that directory I created two more. One for FireFox and one for ThunderBird.

[mike@localhost ~]$ cd /mnt/Moz_Share/Mike[mike@localhost Mike]$ lsFireFox/  Thunderbird/[mike@localhost Mike]$

Now for the fun part. You need to copy your data folder either from your Windows or Linux into the new folder. In linux the mozilla data folder is hidden /home/mike/.mozilla/firefox/b4vptfrz.default. Yours will be different than /b4vptfrz but will end in .default. In Windows it will be Documents and Settings\Michael\Application Data\Mozilla\Firefox\Profiles. Yours will be under your own users name not Michael (unless that is your name ). I copied my /b4vptfrz.default folder to the new folder

$ cp ~/.mozilla/firefox/*.default /mnt/Moz_Share/Mike/FireFox

Follow the same for ThunderBird

$ cp ~/.thunderbird/*.default /mnt/Moz_Share/Mike/ThunderBird

Now we edit the profiles.ini file to guide it to the new data location. This file is in both directories one for ThunderBird and one for Mozilla. This is what my profiles.ini looks like in Linux. Thunderbird;

 [General]StartWithLastProfile=1[Profile0]Name=defaultIsRelative=0Path=/home/mike/Moz_Share/Mike/Thunderbird/6qayv6i6.default

Mozilla

[General]StartWithLastProfile=1[Profile0]Name=defaultIsRelative=0Path=/home/mike/Moz_Share/Mike/FireFox/b4vptfrz.default

This is what my profiles.ini looks like in Windows. Thunderbird;

[General]StartWithLastProfile=1[Profile1]Name=MichaelIsRelative=0Path=D:\Mike\Thunderbird\6qayv6i6.defaultDefault=1

Mozilla;

[General]StartWithLastProfile=1[Profile0]Name=defaultIsRelative=0Path=D:\Mike\FireFox\b4vptfrz.default

Note: that this line IsRelative=1 is changed to IsRelative=0 and thePath= line now directs to the new data folder location (under windows the / should be \). Also make sure the Path= points to your path. Do both profiles.ini files one for Mozilla and one for ThunderBird in Windows and in Linux. Now enjoy .

Thanks Boilertech for testing and writing this up for us . . . . . this is great info ! Bruno

[Bruno]

PASSWORD PROTECT LILOIf your Linux computer is accessible to more people then just yourself, and you want to beef up security you might think about a few extra measures:1). Password protect your BIOS so people can not use a Live CD to access your Linux partitions.2). Password protect your Lilo bootloader so it can not boot in "single user mode" ( in runlevel 1 any user can give root commands without needing a password ) 3). Password protect Lilo so it will not boot at all without the lilo-password.We will explore a few possible setups:First we set a password Lilo will need before it will allow you to choose the OS you selected to boot ( Linux or Windows ). Here is an example of how the /etc/lilo.conf file should look like ( for the example I will set the password to "L1n3&ux9" ):

default="Linux"boot=/dev/hdamap=/boot/mapkeytable=/boot/us.kltmenu-scheme=wb:bw:wb:bwpromptnowarnpassword=L1n3&ux9timeout=100message=/boot/messageimage=/boot/vmlinuz ........ label="Linux"........ root=/dev/hdb1........ initrd=/boot/initrd.img........ append="acpi=ht splash=verbose"........ vga=788 ........ read-onlyother=/dev/hda1 ........ label="windows" ........ table=/dev/hda

In the next example we will set a password only for the Linux OS . . . . booting Windows will not need a password:

default="Linux"boot=/dev/hdamap=/boot/mapkeytable=/boot/us.kltmenu-scheme=wb:bw:wb:bwpromptnowarntimeout=100message=/boot/messageimage=/boot/vmlinuz........ password=L1n3&ux9........ label="Linux" ........ root=/dev/hdb1........ initrd=/boot/initrd.img ........ append="acpi=ht splash=verbose"........ vga=788 ........ read-onlyother=/dev/hda1........ label="windows"........ table=/dev/hda

In our last example you can boot both Linux and Windows without password . . . but if you try to boot Linux with extra arguments ( like "linux 1" to boot in single user mode ) you will need the password:

default="Linux"boot=/dev/hdamap=/boot/mapkeytable=/boot/us.kltmenu-scheme=wb:bw:wb:bwpromptnowarntimeout=100message=/boot/messageimage=/boot/vmlinuz........ password=L1n3&ux9........ restricted ........ label="Linux" ........ root=/dev/hdb1 ........ initrd=/boot/initrd.img........ append="acpi=ht splash=verbose"........ vga=788........ read-onlyother=/dev/hda1 ........ label="windows" ........ table=/dev/hda

NOTE 1: After changing the /etc/lilo.conf file be sure to give the command "/sbin/lilo" to write the new Lilo to the MBR !NOTE 2: Because in normal cases everybody can read the lilo.conf file you should change permissions on it so only root can read it:

# chmod 600  /etc/lilo.conf

After protecting Lilo and the BIOS with a password the only way to tamper with your computer is fiddling with the jumpers on the motherboard to reset the BIOS, so if it is located in a public place you might want to physically lock the box as well. Bruno

[Bruno]

REDO-LILO / REDO-MBR ( PCLos )Reading the documentation of PCLos 9.2 lately I came accross a nice new little tool "redo-lilo". This is a tool that allows you to restore the bootloader of a HD installed PCLos using the Live CD.See when you dualboot Windows and Linux you sometimes have to go through the routine of reinstalling Windows, but with reinstalling Windows you will automatically overwrite the MBR and thus loose your Lilo bootloader.Now, with the new script "redo-lilo" included on the PCLos 9.2 you can re-write your PCLos Lilo bootloader to the MBR and in no time you will be smiling again.Here are the instructions from the PCLos documentation:

You will need your live CD. Put in the Live CD, and reboot the computer. Eventually you will get to the login screen. I recommend that, on this occasions, you log in as root.What you do next depends on the version of Live CD you have. With preview 0.92, we have included a little tool for you called redo-lilo. You can run this tool to repair the broken bootloader for you! Open a konsole ( Startmenu -> Terminals -> Terminal Program (Konsole) ) and type "redo-lilo". Follow the on-screen directives and when done, reboot to your repaired bootloader and log in to your PCLinuxOS installation.

NOTE: In PCLos 94 the name of the utility changed to "redo-mbr" . . . and BTW at your wish it does restore Grub to the MBR as well. ;) Bruno

[Bruno]

RUNNING XFDRAKE( To reconfigure X in PCLos and Mandriva )People running PCLos or Mandriva are lucky, when they loose X there is an easy tool to reconfigure it: "XFdrake"Here is step by step what you need to know about running XFdrake:- Boot in runlevel 3 ( see Booting in Runlevel 3 ( Trick with Lilo )- Next at the prompt log in as "root" and type "XFdrake" ( case sensitive ) . . you will get a wizard to configure your graphics card and monitor . . . .In general it will detect the correct settings, just check them ( move with the tab key and arrow keys ) . . . . - Next, test the settings with the "Test"-button ( if you get a multicolored screen with an OK-box in the middle and you see the mouse cursor the settings are correct and you can click OK ) . . . . . . then close XFdrake.Finally log out as root with "Ctrl+D", log in as "user" and type "startx" . . . . and you should be back smiling again. BrunoPS: Running "XFdrake --auto" is a shortcut to the above and works on most common hardware.

[Bruno]

THE "AT" COMMANDToday we have something simple that actually is a bit complicated to explain . . . . . it is about the command "at". This command "at" lets you execute a command or script at a later time, you can set the time in many different ways and even have the result mailed to you after the command has been executed.Now, using "at" is not only just typing the command and hitting the enter-key . . . there is a little more to it, so let me give an example. In the example we want to have the command "play /usr/share/sounds/KDE_Startup.wav" executed at 12:49 . . . . have a look what I see in the terminal:

$ at 12:49 -mwarning: commands will be executed using (in order) a. $SHELL b. login shell c. /bin/shat> play /usr/share/sounds/KDE_Startup.wavat> <EOT>job 7 at 2006-05-01 12:49

- On the 1st line you see the command "at 12:49 -m", meaning execute at 12:49 and the "-m" means mail me when the job is finished.- On the 2nd line it will print some info about the at command and jump to line 3- On the 3rd line you will see the "at>" prompt, at the "at>" prompt you type the command you want to have executed and you hit the enter-key again.- On the 4th line you get the "at>" prompt appearing again, this time you press Ctrl+D and it will print <EOT> - The 5th it will then automatically print the job number and the time the given command will be executed.Next example: here we have a script "/usr/local/bin/backup-script" that we want executed at 12:32 . . . . Again, have a look what I see in the terminal:

# at 12:32 -m -f /usr/local/bin/backup-scriptwarning: commands will be executed using (in order) a. $SHELL b. login shell c. /bin/shjob 8 at 2006-05-01 12:32

On the 1st line you see "at 12:32 -m" like in our first example . . but after that comes "-f" meaning "from file" and "/usr/local/bin/backup-script" which is the path to the file/script I want to have executed.On the 2nd and 3rd line you see the same as we saw on line 2 and 5 of our first example.Okay . . hold on, we are almost there . . . . remember the job numbers? Well, they can come handy if you want to cancel the job before it runs. First we use either "at -l" or "atq" to list the pending jobs:

$ at -l7 2006-05-01 12:49 a bruno8 2006-05-01 12:32 a root

And we see the number of the first job is "7" . . . . now we remove that job with

$ atrm 7

Good . . . . now before I close off there is one last point I would like you to look at and that is the vast amount of different time formats you can use with the command "at" . . here is from the man-page:

At allows fairly complex time specifications, extending the POSIX.2 standard. It accepts times of the form HH:MM to run a job at a spe- cific time of day. (If that time is already past, the next day is assumed.) You may also specify midnight, noon, or teatime (4pm) and you can have a time-of-day suffixed with AM or PM for running in the morning or the evening. You can also say what day the job will be run, by giving a date in the form month-name day with an optional year, or giving a date of the form MMDDYY or MM/DD/YY or DD.MM.YY. The specifi- cation of a date must follow the specification of the time of day. You can also give times like now + count time-units, where the time-units can be minutes, hours, days, or weeks and you can tell at to run the job today by suffixing the time with today and to run the job tomorrow by suffixing the time with tomorrow. For example, to run a job at 4pm three days from now, you would do at 4pm + 3 days, to run a job at 10:00am on July 31, you would do at 10am Jul 31 and to run a job at 1am tomorrow, you would do at 1am tomorrow.

Have Fun my friends, see you "at 8pm + 7 days" for a new TipB) BrunoPS: See for another example and additional info: Linux.com

[Bruno]

KDESU and GKSUThe official line for "kdesu" and "gksu" is: "Runs a program with elevated privileges" . . . Now, in real life what does this mean ? Let me have a go at it.Imagine there is a program or tool you want to run as "root", if this is a command line tool we already know we have to do "su" ( or "sudo" in case of Ubuntu ). But if it is a GUI tool you want to run as root, and you simply do "su" and start the program from the command line there is a big chance you will be presented a screen full of errors ( or even worse get the Xlib Error ). In these kind of situations the "kdesu" ( for KDE ) and the "gksu" ( for Gnome ) are the ticket.Here is an example, you are running KDE and you want to open a file in Kedit because you want to have an easy way to edit the ( /etc/X11/xorg.conf ) file as root, what you do is give the following command as user:

$ kdesu kedit /etc/X11/xorg.conf

The "kedit /etc/X11/xorg.conf" part of the command is for opening the file in Kedit, but the "kdesu" that precedes that command triggers a box to pop up where you are asked to give the root-password. After you give the password Kedit will open with the file loaded and you can edit it ( as if you were root ).The same story goes for the "gksu" command if you are a Gnome user. It avoids error messages and allows you to run any GUI based tool as root without actually having to log out as "user" and log in as "root". . . . Using kdesu and gksu is a much safer practice.Keep your system safe. BrunoPS: In some distros "gksu" is replaced by "gnomesu" or "gtksu"

[Bruno]

NO CAPSLOCK !Does this happen to you ? Ever had the urge to violently remove the Cap Lock key from your keyboard because you accidentally kept hitting it ? Relax, I think we have a solution for this problem.Linux offers you an effective way to disable Caps lock and if you want you can even add a new function to that key.Basically the command to disable the Caps Lock key ( for the current session only ) would be:

$ xmodmap -e "remove Lock = Caps_Lock"

Now, there are a few ways to make this permanent, just pick the one that works best for you: 1). Add remove Lock = Caps_Lock to the /etc/X11/Xmodmap or the ~/.xmodmaprc file ( But in my Mandriva this did not help so see the next option )2). Make a bash script called nocapslock with the text:

#!/bin/bashxmodmap -e "remove Lock = Caps_Lock"#End script

And make the file executable with

$ chmod 755 nocapslock

Finally if you run KDE place the script in /home/bruno/.kde/Autostart, if you run Gnome you can make a directory /usr/share/gnome/autostart and place the script in there and at next login you get a dialog that will ask you if you want to enable the script for future logins in Gnome.This should take care of disabling the Caps Lock key. But that is not all you can do, you could even give the Caps Lock key another function ( make it another Enter-key with "keycode 66 = Return" ) or even swap the Ctrl key with the Caps Lock key with the following script:

#!/bin/bashremove Lock = Caps_Lockremove Control = Control_Lkeysym Control_L = Caps_Lockkeysym Caps_Lock = Control_Ladd Lock = Caps_Lockadd Control = Control_L#End script

Have a look in "man xmodmap" and get creative with your keyboard. Bruno

[Bruno]

COUNTING WORDS The "wc" commandThere are people that love to count beans, myself at the end of the day I love to count the words I have written. <g>And sure, Linux has just the command for that: "wc"The "wc"command comes with a few options:

-c, print the byte counts-m, print the character counts-l, print the new line counts-L, print the length of the longest line-w, print the word counts

When I execute the command on this little bit of text I am typing right now I get:Words:

$ wc -w test.txt184 Desktop/text.txt

Lines:

$ wc -l test.txt50 Desktop/text.txt

Characters:

$ wc -m test.txt1045 Desktop/text.txt

Longest line:

$ wc -L test.txt118 Desktop/text.txt

Sure you can feed the "wc" command more then one file in a different format at once:

$ wc -w test.txt xgl.doc NewTips.txt post.kwd 184 test.txt 280 xgl.doc 209 NewTips.txt1161 post.kwd1834 total

And here is one to try at home . . . . cd to your Documents folder and do "wc -w *.odt" ( or "wc -w *.doc" if that is your preferred format )Isn't that fun . . . . . . at least you get the impression you weren't all that lazy after all . . . . ;) Bruno

[Bruno]

RPM: SPECIAL TRICKSThere is a lot more to the rpm command then you might suspect on first sight. What I want to do in this tip is to cherry pick some real nice nuggets from the endless list of options.You probably already know the most basic way to install/upgrade an RPM package:Installing:

# rpm -ivh amarok-1.4.1-4mdk.i586.rpm

Upgrading:

# rpm -Uvh amarok-1.4.1-4mdk.i586.rpm

Removing:

# rpm -e amarok

But now for the special tricks, did you know you can also let the rpm command download and install the file for you ? ( works on http and ftp )

# rpm -ivh http://kev.coolcavemen.com/static/repository/mandriva/2006.0/RPMS/amarok-1.4.1-4mdk.i586.rpm

And that you can downgrade the package you installed ( because the new one has a bug ? ):

# rpm -Uvh --oldpackage amarok-1.3.1-3mdk.i586.rpm

You can get detailed information on the package before installing it:

# rpm -qip amarok-1.4.1-4mdk.i586.rpm

This even works on a file you did not yet download:

# rpm -qip http://kev.coolcavemen.com/static/repository/mandriva/2006.0/RPMS/amarok-1.4.1-4mdk.i586.rpm

Also, you can get a complete list of all the files a package will install:

# rpm -qlp amarok-1.4.1-4mdk.i586.rpm

And sure this works on a file you have not yet download too:

# rpm -qlp http://kev.coolcavemen.com/static/repository/mandriva/2006.0/RPMS/amarok-1.4.1-4mdk.i586.rpm

Now 4 commands to get some info on packages that are already installed . . . first put a complete listing in your /home:

# rpm -qa | sort -f > installed_rpms.txt

( Note: There is a nice Tip at Distrowatch showing how to get a package list in other distros )Here is how you get info on a single package:

# rpm -qi amarok

And a full list of the files belonging to an installed package:

# rpm -ql amarok

Finally if you are curious what package installed a file you found on your computer:

# rpm -qf /usr/share/apps/zeroconf/_shoutcast._tcp

Well, you'll have to admit, the rpm command is pretty versatile . . . . and there is more, just have a look at "man rpm" and you will see there is at least a hundred different options listed. Bruno

[Bruno]

* Due to limitations of the forum software this how-to is split over 2 postsINSTALLING MANDRIVA 2007( General instructions )Please first read the erratum: http://qa.mandriva.com//twiki/bin/view/Main/MandrivaLinux2007Errata- PreparationIf this is your first Linux install, check out Basic Rules for InstallIf you are replacing a previous Mandrake Install back up:- Your browser plugins located in /usr/lib/mozilla/plugins- The ~/.evolution directory ( When I restore it, I chown (change ownership) it back to "chown -R bruno:bruno evolution" )- The ~/.galeon/bookmarks.xml ( or other bookmarks )- Personal things in your /home directory- Your /etc/lilo.conf ( if you are booting mutiple distros )- Your /etc/hosts, /etc/aliases, /etc/sensors.conf, /etc/rc.d/rc.local, ~/.bashrc, ~/.exrc if you made any modification to these files.- Your /usr/local/bin if it holds any of your custom scripts.- Set your BIOS to boot from CD and disable PNP aware OS.- Put the first CD in the CD-ROM drive and boot your computer.- Install1st screen: The welcome screenSelect "Installation" with your arrow keys and Press EnterBefore the GUI comes back, the installer is loading into memory and devices are being configured.2nd screen: Language selection <------- Click to enlargeThe default is US English, Press Next3rd screen: License agreement <------- Click to enlargeSelect "accept" and Press Next4th screen: Is this an install or an upgrade ? <------- Click to enlargeTick the box of "install" and Press Next. Advice: NEVER use Upgrade !!!5th screen: Security level <------- Click to enlargeATTENTION: By default the security level is set to "high", change this to "Standard"Fill in "root" or your email address and Press Next6th screen: The DrakX Partitioning wizard found etc. etc. <------- Click to enlarge- If you have your partitions already made: tick the box "use existing partitions" and Press Next- If you still have to make partitions, or want to change the size of the existing ones: tick the box "Custom Disk Partitioning" and Press Next You will be taken to the very intuitive and easy partitioning tool. Make a 6G partition for / and a 2G for /home.7th screen: Choose file Mount points <------- Click to enlargeChose the partitions where you want / and /home and Press Next( Everybody using partitions for /tmp and /usr too . . you know what to do )8th screen: Choose the partitions you want to format <------- Click to enlarge. . Leave the /home box unchecked if you want to keep your mail addresses and personal settings Press Next9th screen: Installation media <------- Click to enlargeHere you are asked to check the installation media ( CDs, DVD ) only check those you have and Press Next10th screen: Packages <------- Click to enlargeDo like in the screen shot: tick all the boxes on the left, KDE and Gnome on the right and Press NextNOTE: Including Gnome will also give you all the gnome programs you can also use in KDE . . so even if you intend to never use Gnome it is better to install it anyway.Now the install really starts. It takes about 16 minutes and you have to change CDs a few times* Will be continued in next post . . . . . .

[Bruno]

11th screen: Root password <------- Click to enlargeFill in your root password twice and Press Next12th screen: Adding a user <------- Click to enlargeFill in name twice and password twice and Press Accept user13th screen: Adding a user ( again ) <------- Click to enlargeHere you can add another user, or leave it empty and Press Next14th screen: Auto login <------- Click to enlargeDe-select the box, you do not want this, and Press NextNOTE: It is safer to not use this feature, and it makes sure that you can choose at boot what window manager to start. Also if you ever get a corrupted /home directory the non-autologin makes fixing a lot easier.15th screen: Boot loader <------- Click to enlargeSelect "First sector of drive ( MBR )" and Press NextNOTE: It will automatically include your Windows partition for dual boot16th screen: SummaryThis is very important . . check all the settings by clicking on the Configure button, look at the difference I have in the two screenshots: <------- Click to enlargeBefore configuring <------- Click to enlargeAfter configuringNOTE: While configuring the Graphic interface you can be pesented this sreeen: <------- Click to enlargeIf you don't have a recent model Graphics card it is safer to uncheck "Enable translucency" and "Use hardware accelerated mouse pointer"( You could experiment with these settings any time after the install by running XFdrake )17th screen: UpdatesNOTE: This feature rarely works, you will have to do the updates in the MCC after the first reboot.So . . . say NO and Press Next18th screen: Complete. . remove your CD and Press Reboot- After the install:After the reboot you absolutely have to install: "anacron", and get the Updates ( see and subscribe to This thread )Additionally you can add: xmms, xmms-alsa, aumix, galeon, gkrellm, kedit, mplayer, xine etc. etc.NOTES: Here are a few quick bug-fixes.1). Fix LinDVD error:

# cp /usr/share/lindvd/libivimandriva.so /usr/lib/# ldconfig

2). KDE menu, errormessage when choosing "System" --> "Configuration" --> "Packaging" --> "Install, Remove and Update Software"The fix: Start up the menueditor and change the command in the relevant menu entry from "/usr/bin/drakconf --start-with=install-software" to "rpmdrake --root"3). Updatedb errorThe fix: Install mlocate ( will replace slocate )4). Problems with k3b when trying to burn a dvd iso. It is a conflict with available memory and growisofs v6.0The fix: Give the command "# ulimit -l unlimited" as root prior to starting k3b (as root) to burn dvd's.Also read the release notes: HereHave FUN ! Bruno

[Bruno]

INSTALLING FEDORA CORE 6( Short instructions )Please first read the releasenotes: RELEASE-NOTES-en_US.html- Install1st screen: The welcome screen Press Enter2nd screen: Install or UpgradeMy choice was "Install Fedora Core", Press Next3rd screen: Partitions <------- Click to enlargeIf you are using existing partitions, do as in the screenshot and change the box to "Create custom layout" and Press Next4th screen: The partition tool <------- Click to enlargeHighlight the partition you want to use and click the Edit button and you will see: <------- Click to enlargeIn the pop-up select the mount point ( / ) and check the box to format the partition, then Press OK5th screen: Bootloader <------- Click to enlargeATTENTION: If you want to add fedora to the bootloader of another distro, please install the fedora grub in the / partition: check the box "Configure advanced bootloader options" and Press NextIf you want to use the Fedora bootloader the default settings are fine.6th screen: Install the bootloader record onIn case you did choose "Configure advanced bootloader options" in the 5th screen you get: <------- Click to enlargeHere you can check the box that will install the grub bootloader of Fedora in the / partition ( in the example above it is /dev/hda11 ) . . this way you can easily add it to the to the bootloader of the distro you are currently using. Press Next7th screen: Network Devices <------- Click to enlargeIf you use DHCP . . . accept the default and Press Next8th screen: Location <------- Click to enlargeThis is where I live . . . . Change yours to suit your location and Press Next9th screen: The Root Password <------- Click to enlargeType in the root password twice and Press Next10th screen: Packages <------- Click to enlargeDo like in the screen shot, "Office and Productivity" is checked by default, choose "Software development" as well and Press NextNOTE: If you want KDE, check the box "Customize now" and in the next screen you can check the box for KDENOTE 2: When choosing "Fedora Extras" you need a fast broadband connection because it will download a lot of files from the FTP server and this might be a major increase of the time your install will take.11th screen: Now the install really starts. <------- Click to enlarge. . . when finished you have to reboot and after rebooting you will get Stage 2 of the install where it will let you create a user with user password.Have FUN ! Bruno

[Bruno]

CHANGE YOUR SHELLThere was a question on the forum: "How do I change shell ?" . . . And the answer is simple, but let me first tell you something about shells.The default shell for most distros is the bash shell ( see Bash ), but there are more shells available, just type the following command and the ones for your distro will be listed:

$ chsh -l

This commands will show you the shells that are mentioned in the /etc/shells file.On my distro the above command will show:

/bin/bash/bin/csh/bin/ksh/bin/sh/bin/tcsh

Now imagine I would want to switch to the /bin/sh shell, I can do that just for the session or permanently:1). For temporary changing the shell you just give the command:

$ /bin/sh

and you will see the prompt changing to a different one ( again, on my system it shows: "sh-3.00$" ).You can change it back by simply giving the command:

$ /bin/bash

2). For permanently changing the shell you can use the "chsh" command:

$ chsh -s /bin/sh

You will be prompted for a password and for confirmation it will show you for what user you are changing the shell.Now, that was an easy one, wasn't it ? BrunoA note from finotti on the forum: In some systems (using NIS) you might have to use:

$ ypchsh <user>

and answer the questions.

[Bruno]

URPMI SOURCES MANDRIVA 2007Here are the extra sources you can add to the package manager of Mandriva 2007 in order to get extra software. Most everybody can add, but a few ( the last 3 ) are only for Mandiva Club Members.Please take a serious note of the following:1). Only have the Main, Contrib and Update source active all the time. And only if you can not find the software you are looking for, activate the additional sources in the MCC - but remember to de-activate them immedeately after installing the package !2). Because sources need updating do a regular "# urpmi.update -a"3). If you are on dialup you can replace the "hdlist.cz" in the code with "synthesis.hdlist.cz" this means you will get a condensed list with less details in the description of the packages . . but you'll get it faster.4). "# urpmq --list-media active" will list the "active" sources.[/color]Here they are: ( Dont click on the links but paste them in a root-terminal ) YOU HAVE TO BE ON LINE !All commands are ONE line.- STANDARDMain:

# urpmi.addmedia --wget "2007_main.release" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandrakelinux/official/2007.0/i586/media/main/release/ with ./media_info/hdlist.cz

Contrib:

# urpmi.addmedia --wget "2007_contrib.release" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandrakelinux/official/2007.0/i586/media/contrib/release/ with ./media_info/hdlist.cz

- BACKPORTS ( Warning: Only use with great care, can lead to dependency problems ! ) Main Backports:

# urpmi.addmedia --wget "2007_main.backports" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandrakelinux/official/2007.0/i586/media/main/backports/ with ./media_info/hdlist.cz

Contrib Backports:

# urpmi.addmedia --wget "2007_contrib.backports" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandrakelinux/official/2007.0/i586/media/contrib/backports/ with ./media_info/hdlist.cz

- TESTING ( Warning: Only use with great care, can lead to dependency problems ! ) Main Testing:

# urpmi.addmedia --wget "2007_main.testing" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandriva/official/2007.0/i586/media/main/testing/ with ./media_info/hdlist.cz

Contrib Testing:

# urpmi.addmedia --wget "2007_contrib.testing" ftp://ftp.nluug.nl/pub/os/Linux/distr/Mandriva/official/2007.0/i586/media/contrib/testing/ with ./media_info/hdlist.cz

- PLFPLF Free: ( Needs the Contrib source )

# urpmi.addmedia --wget "plf-free" ftp://ftp.free.fr/pub/Distributions_Linux/plf/mandrake/2007.0/free/release/binary/i586 with hdlist.cz

PLF Non-Free: ( Free to download and use, non-free as in licence ) ( Needs the Contrib source )

# urpmi.addmedia --wget "plf-nonfree" ftp://ftp.free.fr/pub/Distributions_Linux/plf/mandrake/2007.0/non-free/release/binary/i586 with hdlist.cz

- PLF BACKPORTS ( Warning: Only use with great care, can lead to dependency problems ! ) PLF Free Backports:

# urpmi.addmedia --wget "plf-free-Backports" ftp://ftp.free.fr/pub/Distributions_Linux/plf/mandrake/2007.0/free/backports/binary/i586 with hdlist.cz

PLF Non-Free Backports:

# urpmi.addmedia --wget "plf-nonfree-Backports" ftp://ftp.free.fr/pub/Distributions_Linux/plf/mandrake/2007.0/non-free/backports/binary/i586 with hdlist.cz

- EXTRAMandrivaClub-NL:

# urpmi.addmedia --wget "MandrivaClub.NL" ftp://ftp.nluug.nl/pub/os/Linux/distr/mandrakeclubnl/2007/i586 with hdlist.cz

Eslrahc:

# urpmi.addmedia --wget "charles-edwards" http://www.eslrahc.com/2007.0/ with hdlist.cz

MandrivaUser-DE:

# urpmi.addmedia --wget "MandrivaUser.de" ftp://ftp.mandrivauser.de/rpm/GPL/2007/RPMS with hdlist.cz

SeerOfSouls: ( Warning: Only use with great care, can lead to dependency problems ! )

# urpmi.addmedia --wget seerofsouls http://seerofsouls.com/mandriva/2007/i586/main/ with hdlist.cz

Thac: ( Warning: Only use with great care, can lead to dependency problems ! )

# urpmi.addmedia --wget Thac http://anorien.csc.warwick.ac.uk/mirrors/thac//2007.0/RPMS with hdlist.cz

- CLUB >>> Only Mandriva Club-Members Club Commercial:

# urpmi.addmedia --wget "club.commercial_x86-32_2007" https://bruno%40forum.com:PASSWORD@dl.mandriva.com/rpm/comm/2007.0/i586/ with hdlist.cz

( Do not forget to replace "bruno%40forum.com:PASSWORD" which are the login: <bruno@forum.com> and the <password> for the club . . the @ in your email address is replaced by a %40 )*** Club Testing:

# urpmi.addmedia --wget "club.testing_x86-32_2007" https://bruno%40forum.com:PASSWORD@dl.mandriva.com/rpm/test/2007.0/i586/ with hdlist.cz

( Do not forget to replace "bruno%40forum.com:PASSWORD" which are the login: <bruno@forum.com> and the <password> for the club . . the @ in your email address is replaced by a %40 )*** Club Club:

# urpmi.addmedia --wget "club.club_x86-32_2007" https://bruno%40forum.com:PASSWORD@dl.mandriva.com/rpm/club/2007.0/i586/ with hdlist.cz

( Do not forget to replace "bruno%40forum.com:PASSWORD" which are the login: <bruno@forum.com> and the <password> for the club . . the @ in your email address is replaced by a %40 )NOTE 2: The sources marked *** are not yet available ! Bruno

[Bruno]

UBUNTU RESCUE MODEAlmost every distro has its own way to enter "rescue-mode", a text terminal where you have root permissions and can give the badly needed commands to save your install or restore the access to the GUI environment.There are 2 ways to enter "rescue-mode" in Ubuntu ( Kubuntu, Xubuntu ):1). The easiest one is to choose:

Ubuntu, kernel 2.6.XX-XX-XXX (recovery mode)

from the boot menu.If the boot menu is hidden, simply press the Esc key to make it show up.2). The other way is to use the installation CD, and at the very first screen, at the "boot:" prompt type "rescue" and next follow the instructions that are given. BrunoYou can find a lot of helpful Ubuntu info in the Ubuntu Starter Guide