Linux Operating system - Debian, Fedora, Centos, Ubuntu - Linux stuff - http://www.go2linux.org

kernel panic - not syncing

ggarron — Tue, 18 Nov 2008 18:21:04 -0800

It is true that when you start using Gentoo, you learn a lot about Linux, because it appears some problems that you have to solve, and you need to understand something before you can fix it.

That was the case when I installed Gentoo Linux at my office, I do already have Ubuntu Linux installed there, so I followed the alternate method of installation which is really easy cause you have a running system with browser and Internet while installing so, you can be reading the instructions, and also googling if you find problems.

But, following that method made me make a mistake and as soon as I tried to boot into my new Gentoo, I got this error:

Kernel panic - not syncing:VFS: Unable to mount root fs on unknown-block (1,2)

The problem was on two files,

/etc/fstab and /boot/grub/grub.conf (aka /boot/grub/menu.lst)

You may have the problem only in one of them.

How do this files work?

the grub.conf file tells Linux where the Kernel is and also where root partition is.

title Gentoo Linux 2.6.25-r8
root (hd2,5)
kernel /boot/kernel-2.6.25-gentoo-r8 root=/dev/hdc7

This is part of my grub.conf file.

The root(hd2,5) is saying Linux where is the boot partition and it means, Third hard disk (the 0 counts and is the first disk) and sixth partition, in that disk. so, it is /dev/sdc6 or /dev/hdc6.

the next line is saying where to find the kernel and the root partition.

Then, is the fstab file, which tells Linux the partitions to mount, and where to mount them.

/dev/hdc6       /boot   ext2    defaults,noatime        1 2
/dev/evms/sda5  none    swap    sw                      0 0
/dev/hdc7       /       ext3    noatime                 0 1

This is part of my /etc/fstab file, and it is telling Linux to mount /dev/hdc6 as /boot and /dev/hdc7 as root partitions.

This configuration works now, but when I first wrote this files (by hand as Gentoo needs 'cause there is no automatic tool to make it for you), I entered sdc* where I should have write hdc* this was because Ubuntu names all partitions as s* even if they are ATA and not Serial ATA.

This not only happens in Gentoo, I have seen a lot of people asking for this error in forums, and all you need is to double check this two files, because is almost sure that the problem is in one or in both of them.

Small tip, how to recreate fluxbox menu

ggarron — Mon, 17 Nov 2008 16:30:57 -0800

If you like me use Fluxbox may be aware that when you install a new program it is not automatically added to the menu, yes you can always edit it manually and add the new program to fluxbox menu.

But you can also run:

fluxbox-generate_menu

Then from the old menu choose restart, and voila, you will have almost all your installed applications in the menu.

Gentoo Intel Core 2 Duo CPU E6550 - XFX Pine GeForce 7300 SE - Sound (ICH8 Family)

ggarron — Sun, 16 Nov 2008 19:12:29 -0800

Well, finally I have all my hardware working with Gentoo, I have an Intel Core 2 Duo, with GeForce 7300 from Nvidia and an Intel ICH8 audio card, which is integrated in my mother board.

You may see the output of the hwinfo command in my PC here

And the output of lspci below

00:00.0 Host bridge: Intel Corporation 82P965/G965 Memory Controller Hub (rev 02)
00:01.0 PCI bridge: Intel Corporation 82P965/G965 PCI Express Root Port (rev 02)
00:03.0 Communication controller: Intel Corporation 82P965/G965 HECI Controller (rev 02)
00:19.0 Ethernet controller: Intel Corporation 82566DC Gigabit Network Connection (rev 02)
00:1a.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Contoller #4 (rev 02)
00:1a.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #5 (rev 02)
00:1a.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #2 (rev 02)
00:1b.0 Audio device: Intel Corporation 82801H (ICH8 Family) HD Audio Controller (rev 02)
00:1c.0 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 1 (rev 02)
00:1c.1 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 2 (rev 02)
00:1c.2 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 3 (rev 02)
00:1c.3 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 4 (rev 02)
00:1c.4 PCI bridge: Intel Corporation 82801H (ICH8 Family) PCI Express Port 5 (rev 02)
00:1d.0 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #1 (rev 02)
00:1d.1 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #2 (rev 02)
00:1d.2 USB Controller: Intel Corporation 82801H (ICH8 Family) USB UHCI Controller #3 (rev 02)
00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 02)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev f2)
00:1f.0 ISA bridge: Intel Corporation 82801HB/HR (ICH8/R) LPC Interface Controller (rev 02)
00:1f.2 SATA controller: Intel Corporation 82801HB (ICH8) 4 port SATA AHCI Controller (rev 02)
00:1f.3 SMBus: Intel Corporation 82801H (ICH8 Family) SMBus Controller (rev 02)
01:00.0 VGA compatible controller: nVidia Corporation G72 [GeForce 7300 SE] (rev a1)
03:00.0 IDE interface: Marvell Technology Group Ltd. 88SE6101 single-port PATA133 interface (rev b1)
07:03.0 FireWire (IEEE 1394): Texas Instruments TSB43AB22/A IEEE-1394a-2000 Controller (PHY/Link)

Read how to gentoo, nvidia, X and fluxbox to know how to make Nvidia and X work.

And for the sound, here are the steps I followed to make it work.

First compile the kernel, I am using

Linux gentoo 2.6.25-gentoo-r8 #7 SMP Sun Nov 16 16:29:29 BOT 2008 i686 Intel(R) Core(TM)2 Duo CPU E6550 @ 2.33GHz GenuineIntel GNU/Linux

That is the output of uname -a

And my Kernel configuration file is here

Check that the sound section is:

#
# Sound
#
CONFIG_SOUND=y

#
# Advanced Linux Sound Architecture
#
# CONFIG_SND is not set

#
# Open Sound System
#
# CONFIG_SOUND_PRIME is not set
CONFIG_HID_SUPPORT=y
CONFIG_HID=y
# CONFIG_HID_DEBUG is not set
# CONFIG_HIDRAW is not set

And the I2C hardware bus support is:

#
# I2C Hardware Bus support
#
# CONFIG_I2C_ALI1535 is not set
# CONFIG_I2C_ALI1563 is not set
# CONFIG_I2C_ALI15X3 is not set
# CONFIG_I2C_AMD756 is not set
# CONFIG_I2C_AMD8111 is not set
CONFIG_I2C_I801=m
# CONFIG_I2C_I810 is not set
# CONFIG_I2C_PIIX4 is not set
# CONFIG_I2C_NFORCE2 is not set
# CONFIG_I2C_OCORES is not set
# CONFIG_I2C_PARPORT_LIGHT is not set
# CONFIG_I2C_PROSAVAGE is not set
# CONFIG_I2C_SAVAGE4 is not set
# CONFIG_I2C_SIMTEC is not set
# CONFIG_SCx200_ACB is not set
# CONFIG_I2C_SIS5595 is not set
# CONFIG_I2C_SIS630 is not set
# CONFIG_I2C_SIS96X is not set
# CONFIG_I2C_TAOS_EVM is not set
# CONFIG_I2C_STUB is not set
# CONFIG_I2C_TINY_USB is not set
# CONFIG_I2C_VIA is not set
# CONFIG_I2C_VIAPRO is not set
# CONFIG_I2C_VOODOO3 is not set

Now that you have your kernel configured, according to your own needs, lets install the alsa drivers.

echo "media-sound/alsa-driver" >> /etc/portage/package.keywords

To unmask Alsa Drivers.

echo "media-sound/alsa-headers">>/etc/portage/package.keywords

To unmask Alsa Drivers dependencies.

emerge alsa-driver alsa-utils

To install the drivers and alsa-utils package.

Well, now configure your card.

alsaconf

and follow the instructions there.

Lets start alsasound daemon.

/etc/init.d/alsasound start

And make it start every time you boot your Linux.

rc-update add alsasound boot

Add yourself to the sound gruop

gpasswd -a audio

replace username with your username, and some other you may want to add to that group, and have access to sound.

To set the volume run:

alsaconfig

Be sure to unmute the master, the front and PCM channels

That should be all, now you should have video and sound working with Gentoo.

How to kill user's processes and logout the user

ggarron — Sat, 15 Nov 2008 06:58:14 -0800

The other day a friend of mine was asking me how to stop all users' processes and then logout him.

Well maybe the first thing you need is to send a message to the user, so he can actually save his work.

to do that you may use the command wall to let your users know you are about to log them out.

Now at the given time end all of your users' applications, using pkill

sudo pkill -u username

replace username with every username you have in your system, you can also use.

who | awk '{ printf ("%s",$1 "\n"); }'| grep -v root | xargs -I {} -t pkill -u $1{}

This way you will all all users' processes, be careful using this.

You can also use the command skill but in its man page it says it is obsolete.

skill -KILL -u username

Use this command carefully, as you may make your users loose their jobs.

How to broadcast a message to all users - using wall -

ggarron — Sat, 15 Nov 2008 06:01:29 -0800

Sometimes as the administrator of a Linux Operating System Server, y may need to send a message to all users in a multi-user system.

There are some different ways to do this, but we will now see just one of them.

We will use wall

As the main input of wall is a file, we will first create our message file.

Let's say you want to tell users that in two more ours the main SQL database is going to be unavailable because of maintenance.

So type:

echo 'Please note that in two more hours, and for one hour, you will not be able to use the SQL database, please save all your job before, and quit any application using it'> message.txt

OK, now we have our message ready, it is time to send it to the users.

wall < message.txt

And something like this will appear on all terminals open.

Broadcast Message from root@debian                                             
        (/dev/pts/3) at 9:56 ...                                               
                                                                               
Please note that in two more hours, and for one hour, you will not be able to u
se the SQL database, please save all your job before, and quit any application 
using it

Gentoo + X + Nvidia + Fluxbox

ggarron — Sat, 01 Nov 2008 11:08:31 -0700

There is plenty of information about Gentoo (Thanks God!), I am going to write here a very little how-to install Gentoo, then X, the Nvidia drivers, and Fluxbox, I will not go into details about Gentoo installation as there is enough in the official page.

Once you have your Gentoo Linux running, you can go to install nvidia-drivers, but first lets install sudo -Optional- (I like that sice I have used Ubuntu)

emerge sudo

Now edit the sudoers file using the command:

visudo

And enter this line at the end of the file.

your_user ALL=(ALL) ALL

Now continue with the installation

sudo emerge nvidia-drivers

Then load the module into your Kernel,

sudo modprobe nvidia

sudo update-modules

Then install X

sudo emerge xorg-x11

Now configure X

sudo xorgconfig

Follow the instruction on the screen, be sure to know the vertical and horizontal sync rates for your monitor.

Finally install fluxbox

sudo emerge fluxbox

Configure it to be your windows manager

echo "exec startfluxbox" > $HOME/.xinitrc

And start it:

startx

I got this error at this stage:

(EE) NVIDIA(0): Failed to initialize the GLX module; please check in your X
(EE) NVIDIA(0): log file that the GLX module has been loaded in your X
(EE) NVIDIA(0): server, and that the module is the NVIDIA GLX module. If
(EE) NVIDIA(0): you continue to encounter problems, Please try
(EE) NVIDIA(0): reinstalling the NVIDIA driver.

After googling, I found that the problem was that the GLX module loaded was the X.org module and not the nvidia one, so, solve the problem was as easy as enter this at command prompt.

sudo eselect opengl set nvidia

Now I have my first Gentoo with fluxbox on it running!!

Documentation

Nvidia on Gentoo
Nvidia forum

Gentoo gtk circular dependecies

ggarron — Thu, 30 Oct 2008 20:05:28 -0700

I am starting with Gentoo again, this time installing using the alternative method more specific the Knoppix method, but I did from my running Debian Lenny using the chroot method, well I now have my operating system working, but when I tried to install Gnome

emerge gnome

I got an error

Error circular dependencies

After googling, and reading my configuration files I found that the problem was in my /etc/make.conf file where my USE variable were like this:

USE="-qt3 -qt4 -arts -kde dbus hal avahi gnome gtk"

So I took out the gtk and gnome, and installed the gtk package.

emerge gtk+

Which was the package giving the error of circular dependencies... yes I was telling gentoo to install a package with gtk support without having gtk, and when it tries to install gtk+, it tried to install it, with gtk support, hope this helps anybody someday.

Convert Youtube videos to Cell phone format

ggarron — Thu, 16 Oct 2008 13:53:01 -0700

If you want to play a youtube video on your cellular you may need to convert it to the format you cell phone can actually play, I have tested this process with a Sony Ericsson K550i and it worked great, I suppose it should work on almost all modern cellphones.

First thing you need is to download the video from youtube, there are a lot of ways to do that, more than a year ago, I have written this Howto download a Youtube video with wget, but you can now also use some other online tools like, Savevid, check this youtube video to know how to use the page.

Ok, once you have it downloaded in your disk proceed to convert it to a format your cellphone can play, for that we are going to use ffmpeg

First install the application

sudo aptitude install ffmpeg

Now use it in this format:

ffmpeg -i video.mp4 -s 176x144 -vcodec h263 -r 25 -b 12200 -ab 12200 -ac 1 -ar 8000 arma.3gp

The video I have used for this example is this one.

Armageddon Tribute, just cause is one of my daughters favorites.

Just be sure to change the names video.mp4 and arma.3gp accordingly but keep the .3gp extension on the destination.

Blog action day 2008: Linux and Poverty

ggarron — Wed, 15 Oct 2008 08:08:16 -0700

Today is Blog Action Day, and at Go2Linux we are supporting it by spreading the word, I think that Linux is a good way to fight against poverty, think about all the money that goes to software companies.

Lots of people in poor countries can not afford to pay for Microsoft of Mac software, but Linux is free, and work almost the same (do not want to start a debate about which is better), the most of time it is suitable for everybody's needs.

Also if you have the money to buy a expensive Operating System, but Linux can do the job for you why do not donate that money to the organization of your preference and switch to Linux?, Yes there are learning costs, but I still think they are less that buying an Operating System, Anti Virus, Anti spyware, etc.

That is our small contribution to this cause, and hope some of you might think about this.

Talk to your kids about Linux before somebody else does

ggarron — Sun, 12 Oct 2008 05:50:56 -0700

Hi,

I have found this good comic, hope you enjoy it.

Credits to: xkcd

Force your users to change their passwords frequently

ggarron — Sat, 04 Oct 2008 07:18:36 -0700

The users of a Linux Operating system computer, should always take care about security and if you are the admin of a Linux box with lots of users, you are responsible for the security of it, and maybe you should "force" the other users to change their passwords from time to time, to make this use the command chage

Apply this to a user, lets say guillermo

sudo chage --list guillermo

something like this may appear.

$sudo chage --list guillermo
Last password change                                    : May 10, 2008
Password expires                                        : never
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 99999
Number of days of warning before password expires       : 7

Now lets change change its expiry password date.

sudo chage -M 30 guillermo

This will make its password to expire after 30 days of the last change date.

See now the new info:

$ sudo chage --list guillermo
Last password change                                    : May 10, 2008
Password expires                                        : Jun 09, 2008
Password inactive                                       : never
Account expires                                         : never
Minimum number of days between password change          : 0
Maximum number of days between password change          : 30
Number of days of warning before password expires       : 7

Now when I try to login as guillermo, this is what I got:

$ su - guillermo
Password: 
You are required to change your password immediately (password aged)
Changing password for guillermo.
(current) UNIX password: 
Enter new UNIX password: 
Retype new UNIX password: 
Password unchanged
Enter new UNIX password: 
Retype new UNIX password:

I tried to use the same password again the Linux refused to let me use it, so I was forced to pick a new password.

It is good to have the warn days to 3 or more days, so the user may have time to think a new good password, otherwise will use the first thing he/she may read around resulting in a weak password, which is worse that not changing the original one.

To set the warn days use this command.

sudo chage -W 4 guillermo

Now lets check the info for user guillermo

$ sudo chage --list guillermo
Last password change					: Oct 04, 2008
Password expires					: Nov 03, 2008
Password inactive					: never
Account expires						: never
Minimum number of days between password change		: 0
Maximum number of days between password change		: 30
Number of days of warning before password expires	: 4

Now you may see the new expiry date is Nov 3, 2008 and he will have a 4 days warning about the expiry of his password.

Editing "bluring" your images with GIMP to create bokeh effect

ggarron — Sat, 04 Oct 2008 06:56:26 -0700

If you like the bokeh effect in some pictures you can create it with GIMP, it may not be the same as created at the time of taking the picture (With lenses).

Check out this bokeh pictures

Well now lets see how to create kind of bokeh effect using GIMP

This is the original image:

What we first need to do, is to use the GIMP free select tool.

Then select the contour of the image you want to be highlighted, in this case the flower.

Now with the selection done, press "Ctrl+c" and then "Ctrl+v", and go to layers view.

As you can see it appeared a new layer, a "floating selection (pasted layer)", now right-click on it and select "new layer"

Ok, now we have two layers one with the full image and the other with only our selection.

Select now the layer with the full image, and right-click over the image itself, select the menu "filters" and then, "blur" and then "Gaussian blur".

Select the value that better works for your image.

And the final job is here:

Hope you enjoy it, and thanks goes to: Digital Photography blogs

Alias - create alias for your commands

ggarron — Sat, 20 Sep 2008 08:38:11 -0700

Alias is a command that lets you create command aliases, it is very useful when you usually use commands with options.

As an example in my case I use a lot these commands

du -h

and

df -h

In both cases the "-h" option makes the output be in Kbytes or Mbytes instead of bytes, so it is more human redeable.

To create aliases for this commands just need to enter.

alias du='du -h'

and

alias df='df -h'

Now both du and df will be executed with its -h option.

If you need to de-alias the command just enter:

unalias du

And the alias for du will be deleted.

To view a list of all aliases just type alias with no arguments on the command line.

Running a program in the background

ggarron — Sat, 20 Sep 2008 08:09:09 -0700

If you need to start a program from the command line, and want to recover the command prompt, just add the & symbol to the command.

Example.

firefox

This command will start firefox, but the command prompt will not be available for you to continue working.

firefox &

With this other you will get the prompt back to you, and you can continue using the console for other tasks, It also returns you a number that number is the PID of the application just started.

Making grub menu to wait for you -change timeout-

ggarron — Sat, 20 Sep 2008 07:34:09 -0700

On my PC I have installed, Mandriva, Ubuntu, Gentoo, Sabayon and Debian (my main Linux operating system), but when I turn it on, usually I did not get the grub menu, and I am forwarded directly to Debian, sometimes I have to restart the system to start another Linux flavor.

So, the solution was to put the timeout of grub menu to 15 seconds, so I have enough time to react even when I am not paying attention to the PC startup.

The timeout parameter is stored in the file

/boot/grub/menu.lst

So, to change it edit that file with your favorite text editor. (mine is vim)

sudo vim /boot/grub/menu.lst

and look for the line that contains the string "timeout"

This is how my file looks

## timeout sec
# Set a timeout, in SEC seconds, before automatically booting the default entry
# (normally the first entry defined).
timeout         15

please note that the above text is only part of my menu.lst.

If you want grub to wait for you to take an action before continue, comment the timeout line, or erase it.

whowatch - Monitor who is doing what on your system

ggarron — Fri, 12 Sep 2008 14:17:55 -0700

whowatch is a console application that lets you monitor what different users are doing on the Linux operating system in a given moment, it works in real time.

First install it

sudo aptitude install whowatch

Now to run it just enter whowath in the command line, some screen like this will appear.

If you press ENTER while on a given username you will see the info about the programs that user is running.

Like this:

As you can see below you may see some command that lets you get more info about the user, and the programs being run by him.

If you go to "menu" by pressing F9 from the main menu, you will also be able among other things to send kill, HUB or TERM signals to the processes running, you can also use the keyboard for that with

^K for Kill
^U for HUP
^T for TERM

A pretty useful tool for admins

dpkg: ../../src/packages.c:221: process_queue: Assertion `dependtry <= 4' failed

ggarron — Tue, 09 Sep 2008 14:36:39 -0700

I run a

sudo aptitude full-upgrade

On my Debian Lenny, but once all the packages were downloaded and started to be installed, suddenly the process stopped, then when I run

sudo aptitude reinstall

I got this:

sudo aptitude reinstall
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Reading extended state information      
Initializing package states... Done
Writing extended state information... Done
Reading task descriptions... Done         
The following partially installed packages will be configured:
  cups-driver-gutenprint cupsys-driver-gutenprint debian-faq gxine 
  libregexp-java menu 
0 packages upgraded, 0 newly installed, 0 to remove and 170 not upgraded.
Need to get 0B of archives. After unpacking 0B will be used.
Writing extended state information... Done
dpkg: error processing iptables (--configure):
 package iptables is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing nano (--configure):
 package nano is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing debian-faq (--configure):
 package debian-faq is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing cups (--configure):
 package cups is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing libxine1-bin (--configure):
 package libxine1-bin is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing libregexp-java (--configure):
 package libregexp-java is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: error processing menu (--configure):
 package menu is not ready for configuration
 cannot configure (current status `triggers-awaited')
dpkg: ../../src/packages.c:221: process_queue: Assertion `dependtry <= 4' failed.
E: Sub-process /usr/bin/dpkg exited unexpectedly
A package failed to install.  Trying to recover:
dpkg: ../../src/packages.c:221: process_queue: Assertion `dependtry <= 4' failed.
Reading package lists... Done             
Building dependency tree       
Reading state information... Done
Reading extended state information      
Initializing package states... Done
Reading task descriptions... Done

So, after googling a little, I used dpkg to uninstall manually all the packages listed above,

sudo dpkg -r cups-driver-gutenprint cupsys-driver-gutenprint debian-faq gxine

Then the command

sudo aptitude reinstall

worked again, and I was able to install those packages again.

VMware Server 1.05 fails to start with version 2:1.1.4-2 of libx11-6

ggarron — Sun, 31 Aug 2008 07:34:06 -0700

Some days ago I have updated my Lenny and VMware stop working, this time it was not a problem of a new kernel usually solved reconfiguring vmware, this time the problem was the new version of libx11-6 does not work with vmware, so the solution is to downgrade it to the Etch version.

First create a file called

/etc/apt/preferences

put this content inside:

Package: libx11-6
Pin: release a=stable
Pin-Priority: 1001

Package: *
Pin: release a=testing
Pin-Priority: 500

Then modify your /etc/apt/sources.list

and add the stable (or Etch) lines, mine looks like this:

deb http://ftp.debian.org/debian/ testing main non-free contrib
#deb-src http://mirrors.kernel.org/debian/ lenny main non-free contrib

#deb http://mirrors.xenir.com/debian/ lenny main non-free contrib

deb http://security.debian.org/ testing/updates main contrib non-free
#deb-src http://security.debian.org/ lenny/updates main contrib non-free

deb http://download.skype.com/linux/repos/debian/ stable non-free

deb http://deb.opera.com/opera lenny non-free
#

#stable
deb http://ftp.debian.org/debian/ stable main non-free contrib

Now run

sudo aptitude update

to update your database.

Now run:

sudo apt-get -t stable install libx11-6

that command will downgrade the libx11-6 package to a version that will work with VMWare.

be sure that your output when running VMware is like this to be sure this is your solution:

Locking assertion failure.  Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb6f43767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_unlock+0x31) [0xb6f438b1]
#2 /usr/lib/libX11.so.6(_XReply+0x244) [0xb7dc2c14]
#3 /usr/lib/vmware/lib/libXrender.so.1/libXrender.so.1(XRenderQueryFormats+0x109) [0xb7cae969]
#4 /usr/lib/vmware/lib/libXrender.so.1/libXrender.so.1(XRenderFindFormat+0x4c) [0xb7caef4c]
#5 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7af4180]
#6 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7af4d2c]
#7 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_draw_pixbuf+0x270) [0xb7ac4c14]
#8 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7ad124f]
#9 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_draw_pixbuf+0x270) [0xb7ac4c14]
#10 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_pixbuf_render_pixmap_and_mask_for_colormap+0x255) [0xb7ad0b34]
#11 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d5298]
#12 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d5586]
#13 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d777e]
#14 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_cclosure_marshal_VOID__VOID+0xd1)
[0xb7bea459]
#15 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0 [0xb7bd23a1]
#16 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_closure_invoke+0x1b1) [0xb7bd2076]
#17 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0 [0xb7be96eb]
#18 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_signal_emit_valist+0x91e) [0xb7be8d46]
#19 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_signal_emit+0x38) [0xb7be90b8]
Locking assertion failure.  Backtrace:
#0 /usr/lib/libxcb-xlib.so.0 [0xb6f43767]
#1 /usr/lib/libxcb-xlib.so.0(xcb_xlib_lock+0x2e) [0xb6f4381e]
#2 /usr/lib/libX11.so.6 [0xb7dc1dc9]
#3 /usr/lib/libX11.so.6(XAddExtension+0x2c) [0xb7da423c]
#4 /usr/lib/vmware/lib/libXft.so.2/libXft.so.2(_XftDisplayInfoGet+0x77) [0xb7ca6ed7]
#5 /usr/lib/vmware/lib/libXft.so.2/libXft.so.2 [0xb7ca58b1]
#6 /usr/lib/vmware/lib/libXft.so.2/libXft.so.2 [0xb7ca5d39]
#7 /usr/lib/vmware/lib/libXft.so.2/libXft.so.2(XftDrawPicture+0x10) [0xb7ca5ec0]
#8 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7af29b6]
#9 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7af4d75]
#10 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_draw_pixbuf+0x270) [0xb7ac4c14]
#11 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0 [0xb7ad124f]
#12 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_draw_pixbuf+0x270) [0xb7ac4c14]
#13 /usr/lib/vmware/lib/libgdk-x11-2.0.so.0/libgdk-x11-2.0.so.0(gdk_pixbuf_render_pixmap_and_mask_for_colormap+0x255) [0xb7ad0b34]
#14 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d5298]
#15 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d5586]
#16 /usr/lib/vmware/lib/libgtk-x11-2.0.so.0/libgtk-x11-2.0.so.0 [0xb79d777e]
#17 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_cclosure_marshal_VOID__VOID+0xd1) [0xb7bea459]
#18 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0 [0xb7bd23a1]
#19 /usr/lib/vmware/lib/libgobject-2.0.so.0/libgobject-2.0.so.0(g_closure_invoke+0x1b1) [0xb7bd2076]
vmware: ../../src/xcb_lock.c:77: _XGetXCBBuffer: Assertion `((int) ((xcb_req) - (dpy->request)) >= 0)' failed.

You may want to read:

How to apt-get

at - command to schedule actions

ggarron — Wed, 06 Aug 2008 13:35:12 -0700

One of the most uses I give to this command is to turn the PC off after some time, sure there are other ways.

I like the way you may execute batch jobs at a given time, all you need is:

1. Write your shell script

Which actually is a list of commands in a text file

2. Execute the at command

at now + 5 minutes < $HOME/listofcommands.txt

You can use times like "now", "noon", "midnight", or a date in the format of DD.MM.YY

check man at in order to have more details

Nice IBM adverticing about Linux

ggarron — Wed, 16 Jul 2008 06:28:19 -0700

Hi,

I have found this video on Youtube, take a look at it.

Installing and uninstalling .deb package

ggarron — Sat, 12 Jul 2008 07:05:39 -0700

Debian uses .deb binary packages and you manually install and uninstall them using dpkg tool.

dpkg has lots of options but maybe the most important or used ones are:

-i: Installs and configures a package
-r: Removes the package but keeps the configuration files on your systems, thus you may reinstall it later and does not need to configure it again
-p: Purges a package, meaning it will remove the package and also all configuration files

How to use it

- To install a .deb package

sudo dpkg -i package.deb

- To uninstall a .deb package

sudo dpkg -r package

- To purge a .deb package

sudo dpkg -p package

Moving a window in GNOME

ggarron — Sat, 21 Jun 2008 19:07:37 -0700

If you someday have a window out of your screen or at least the title bar out of your screen as I had today, I was surfing the web using Opera and when I pressed CTRL+F to look for a text in the page the little window appeared too high in the screen that I could not click on the title bar and move it a little down.

Well the solution for this is to press the and hold the ALT key, and click any place on the window to move it.

Tip: If you use the righ button of the mose you can resize it without need to click on the border of the window.

Hope this may help you.

du - Shows the disk space a file or directory is using in your disk

ggarron — Sat, 21 Jun 2008 18:40:21 -0700

This is a very useful command you may use to find which file or directory is filling you disk.

So if you need to check the file and directory size in your home directory you can enter

to switch to your home directory

du -S * | sort -n

This is going to list all files, directiries and sub-directories in size order, and will not include sub-directories' size in directories' size, if you want to have a total size of a directory including its sub-directories, you will have to remove the -S

du * | sort -n

If you want to have the sizes in "human language" I mean in kilos and megas, add the -h parameter.

How to play a DVD video ISO image

ggarron — Sun, 08 Jun 2008 20:47:14 -0700

I have this new video camera Sony that records on mini DVDs, and I got a video from my daughter dancing for the mother's day, I copied it as an image to the hard disk of my Linux Operating System machine

cat /dev/dvd/ > $HOME/video.iso

But now how to play that iso image from my disk with out using my DVD player?

These are the simple commands needed.

sudo mkdir /media/iso

To create a mount point

sudo mount -t iso9660 -o loop /home/ggarron/dvd_video.iso /media/iso

To mount the iso as a DVD

sudo aptitude install gxine

To install the player

gxine dvd://media/iso/video_ts/

To play the DVD movie.

How to delete / purge an email from postfix queue

ggarron — Tue, 03 Jun 2008 05:55:05 -0700

Today I sent an email to a person with an attachment that was not supposed to be sent, so I had to log into my postfix server and delete it from the queue before it leaves the server.

Fortunately, I realized before it leaves, and thanks God the email was big enough for me to have time to log in, find the message and delete it.

If you ever need to delete an email from Postfix queue, you have to follow this steps.

Once logged in your server find the message you are looking for.

sudo postqueue -p

This is going to list the current active queue in your server, something like this.

5642B4D8647* 1683500 Tue Jun  3 08:37:27  xxxxxx@xxxxxxx.com
                                         rrrrrrrrr@hotmail.com

9359B4D82B1* 1635730 Tue Jun  3 08:36:53  xxxxxx@xxxxxxx.com
                                         yyyyyyyy@hotmail.com

The first number is the message ID, the asterisk behind it, denotes that the messages is currently in the process of being sent, to delete it enter.

postsuper -d 9359B4D82B1

This is going to delete message ID=9359B4D82B1, from the queue.

Gmail Manager - Firefox Extension

ggarron — Fri, 23 May 2008 06:51:04 -0700

I want to write a little about this good Firefox extension, maybe lots of you already know it, but for those who does not, here it goes.

As its name says, this extension lets Firefox access your Gmail account, install it from:

Gmail Manager Firefox extension once installed you will have it located at the bottom of your screen, you can manage lots of accounts, which is great, you can see how many emails you have unread, which labels they have, all of that at a glance.

It is also good that you can add sound when there is incoming email, you can also make firefox to directly open your account and create an email when you click on an email address link.

Check it you will love it!, if you are gmail users :)

How to find files, using command line (locate)

ggarron — Wed, 21 May 2008 13:27:20 -0700

Continuing reviewing some of my old posts, I found this one Examples of find command, now I want to show you a faster and easier way to find files.

We are going to use the commands updatedb and locate

updatedb

This command will update the database of the files in a given file system, with no arguments, it will read from / to all file system structure looking for files and archiving the data in the database, located in Debian (/var/cache/locate/locatedb).

There is an option for those using NFS (like me) that you can use to include your NFS file system in the database.

--netpaths=’path1 path2...’

So you can enter a command like this:

sudo updatedb --netpaths=/media/nfs_drive

Now that you have your database updated lets find files.

locate

You just need to enter:

locate filename

and the file named filename will be showed, example:

locate apt-cacher -b

The output is:

/etc/apache2/conf.d/apt-cacher.conf
/etc/apt-cacher
/etc/apt-cacher/apt-cacher.conf
/etc/cron.daily/apt-cacher
/etc/default/apt-cacher
/etc/init.d/apt-cacher
/etc/logrotate.d/apt-cacher
/etc/rc0.d/K20apt-cacher
/etc/rc1.d/K20apt-cacher
/etc/rc2.d/K20apt-cacher
/etc/rc3.d/S20apt-cacher
/etc/rc4.d/S20apt-cacher
/etc/rc5.d/S20apt-cacher
/etc/rc6.d/K20apt-cacher
/etc/rcS.d/S20apt-cacher
/usr/lib/cgi-bin/apt-cacher
/usr/sbin/apt-cacher
/usr/share/apt-cacher
/usr/share/apt-cacher/apt-cacher
/usr/share/apt-cacher/apt-cacher-cleanup.pl
/usr/share/apt-cacher/apt-cacher-format-transition.pl
/usr/share/apt-cacher/apt-cacher-import.pl
/usr/share/apt-cacher/apt-cacher-lib-cs.pl
/usr/share/apt-cacher/apt-cacher-lib.pl
/usr/share/apt-cacher/apt-cacher.pl
/usr/share/apt-cacher/apt-cacher-precache.pl
/usr/share/apt-cacher/apt-cacher-report.pl
/usr/share/apt-cacher/apt-proxy-to-apt-cacher
/usr/share/doc/apt-cacher
/usr/share/man/man1/apt-cacher.1.gz
/var/cache/apt-cacher
/var/cache/apt-cacher/headers/apt-cacher_1.6.1_all.deb
/var/cache/apt-cacher/packages/apt-cacher_1.6.1_all.deb
/var/cache/apt-cacher/private/apt-cacher_1.6.1_all.deb.complete
/var/lib/dpkg/info/apt-cacher.conffiles
/var/lib/dpkg/info/apt-cacher.list
/var/lib/dpkg/info/apt-cacher.md5sums
/var/lib/dpkg/info/apt-cacher.postinst
/var/lib/dpkg/info/apt-cacher.postrm
/var/lib/dpkg/info/apt-cacher.prerm
/var/log/apt-cacher
/var/run/apt-cacher.pid

With the option -b only shows the files where the final part of the name matches the given file name, otherwise, it will show you the full content of the directory /etc/apt-cacher.

Which runlevel are you in?

ggarron — Wed, 21 May 2008 13:06:04 -0700

I wrote a little runlevel explanation, now I will show you how to know in which runlevel your Linux Operating System is actually running.

Which runlevel are you in?

Enter the following command:

sudo runlevel

My output is:

N 2

Switch to other runlevel

To do that enter:

telinit [number of runlevel]

This will change your runlevel to whatever number you enter there, be careful with this command as you can loose data, some programs may not close in an appropriate way.

telinit is actually the same as init, or better said:

telinit = tell init to do change runlevel to:...

1001 RSS readers

ggarron — Wed, 21 May 2008 12:46:09 -0700

Hi, this post is to thank you all for reading this blog, I want to celebrate with you "my readers" because today we surpassed the line of 1000 readers, we are now 1001 readers of this blog.

These are the statics from feedburner.

Thanks again to all of you, and hope you continue reading the posts, and more important that what I write could be useful for your

Automatic Login - Gnome

ggarron — Tue, 20 May 2008 13:11:48 -0700

I think this should work for any Linux operating system using Gnome, I have tested on Debian and Ubuntu.

Well, automatic login will let you avoid to enter your login and password each time you turn on your PC, this could be insecure, but if your computer is physically secured it is Ok to enable this, that could make your booting more smooth.

How to do it?

On Gnome go to:

Systems->Administration->Login Window, you will be prompted for the administrator password, enter it and then select Security tab, once in there select Enable automatic login and select the user you want to be automatically logged in, each time you turn on your PC.