Support and help options

Support options…

Ubuntu Forums..! (this is the first place to contact) Check also local Teams and Forums…

Learn how to report a problem… and how to file a bug report on the…

These are the debugging procedures… and development methods…

Hardware information

What type of graphic card do I have?
$ lspci | grep -i vga
01:00.0 VGA compatible controller: nVidia Corporation NV40.2 [GeForce 6800 LE] (rev a1)$ lspci | grep -i vga
01:00.0 VGA compatible controller: nVidia Corporation Unknown device 0611 (rev a2)
( Ubuntu 7.10 fails to detect the ASUS Geforce 8800GT GPU. It has Nvidia’s 8800 circuitry onboard)
List all PCI devices
$ lspci
00:00.0 Host bridge: nVidia Corporation nForce3 250Gb Host Bridge (rev a1)
00:01.0 ISA bridge: nVidia Corporation nForce3 250Gb LPC Bridge (rev a2)
00:01.1 SMBus: nVidia Corporation nForce 250Gb PCI System Management (rev a1)
00:02.0 USB Controller: nVidia Corporation CK8S USB Controller (rev a1)
00:02.1 USB Controller: nVidia Corporation CK8S USB Controller (rev a1)
00:02.2 USB Controller: nVidia Corporation nForce3 EHCI USB 2.0 Controller (rev a2)
00:05.0 Bridge: nVidia Corporation CK8S Ethernet Controller (rev a2)
00:08.0 IDE interface: nVidia Corporation CK8S Parallel ATA Controller (v2.5) (rev a2)
00:0a.0 IDE interface: nVidia Corporation CK8S Serial ATA Controller (v2.5) (rev a2)
00:0b.0 PCI bridge: nVidia Corporation nForce3 250Gb AGP Host to PCI Bridge (rev a2)
00:0e.0 PCI bridge: nVidia Corporation nForce3 250Gb PCI-to-PCI Bridge (rev a2)
00:18.0 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] HyperTransport Technology Configuration
00:18.1 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Address Map
00:18.2 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] DRAM Controller
00:18.3 Host bridge: Advanced Micro Devices [AMD] K8 [Athlon64/Opteron] Miscellaneous Control
01:00.0 VGA compatible controller: nVidia Corporation NV40.2 [GeForce 6800 LE] (rev a1)
02:08.0 Multimedia audio controller: Creative Labs SB0400 Audigy2 Value
02:09.0 Multimedia video controller: Internext Compression Inc iTVC15 MPEG-2 Encoder (rev 01)See also: hardware report…
List all USB devices
$ lsusb
Bus 003 Device 001: ID 0000:0000
Bus 002 Device 004: ID 04b0:0304 Nikon Coolpix L4 Camera
Bus 002 Device 003: ID 046d:c505 Logitech, Inc. Cordless Mouse+Keyboard Receiver
Bus 002 Device 001: ID 0000:0000
Bus 001 Device 003: ID 046d:c01d Logitech, Inc.
Bus 001 Device 001: ID 0000:0000See also:
$ usbview
How do I show system messages?
Messages from the kernel during boot
$ dmesg
Oct 23 16:31:16 momas-machine kernel: [ 59.610754] agpgart: Found an AGP 3.0 compliant device at 0000:00:00.0.
Oct 23 16:31:17 momas-machine kernel: [ 60.688808] ppdev: user-space parallel port driver

Oct 23 16:31:17 momas-machine kernel: [ 61.309157] apm: BIOS version 1.2 Flags 0x07 (Driver version 1.16ac)General system messages
$ cat /var/log/messages
$ cat /var/log/syslog

See also:
$ man syslogd
How do I determine the CPU type?
$ cat /proc/cpuinfoprocessor : 0 <—- CPU core 0 (or the first physical CPU)
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz <—- CPU type
stepping : 11
cpu MHz : 1998.000
cache size : 4096 KB
physical id : 0
siblings : 2
core id : 0
cpu cores : 2
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe nx lm constant_tsc pni monitor ds_cpl vmx smx est tm2 ssse3 cx16 xtpr lahf_lm
bogomips : 4269.65
clflush size : 64processor : 1

<—- CPU core 1 (or the second physical CPU)
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Duo CPU E6750 @ 2.66GHz

How do I show the total and used memory?
$ cat /proc/meminfoproc
cat /proc/meminfo
MemTotal: 1035636 kB <—- ca. 1GB
MemFree: 278460 kB <—- Free. But total freeable,available = 278460(MemFree) + 361508(Cached) = 640MB
Buffers: 26724 kB
Cached: 361508 kB
SwapCached: 0 kB
SwapTotal: 2048276 kB <— This machine has a swap. It’s active but not needed yet. (see man swapon )
SwapFree: 2048276 kB <—/
VmallocUsed: 63708 kB
VmallocChunk: 46676 kB

See also:
$ free

How many hard drives does this system have?
And what are the partitions and their types?
$ sudo fdisk -lDisk /dev/sda: 160.0 GB, 160041885696 bytes
255 heads, 63 sectors/track, 19457 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x2ac6adf8Device Boot Start End Blocks Id System
/dev/sda1 * 1 2550 20482843+ 83 Linux
/dev/sda2 2551 5100 20482875 83 Linux
/dev/sda3 5101 5355 2048287+ 82 Linux swap / Solaris
/dev/sda4 5356 19457 113274315 5 Extended
/dev/sda5 5356 5482 1020096 83 Linux
/dev/sda6 5483 8522 24418768+ 83 Linux
/dev/sda7 8523 12170 29302528+ 83 Linux
/dev/sda8 12171 19457 58532796 83 Linux

See also
$ cat /proc/partitions

How to check free disk space?
$ df -h /dev/sda1
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda1 20G 17G 1.7G 91% /media/sda1
/dev/sda2 20G 2.9G 16G 16% /media/sda2
/dev/sda3 23G 18G 4.7G 79% /media/sda6-h = human readable outputSee also:
$ du -h
$ df -hiT
How do I report my IP-address?
$ ifconfig -aeth0 Link encap:Ethernet HWaddr 00:1b:fc:de:e0:20
inet addr: Bcast: Mask:
inet6 addr: fe80::21b:fcff:fede:e020/64 Scope:Link
RX packets:411718 errors:0 dropped:0 overruns:0 frame:0
TX packets:319105 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:357701775 (341.1 MB) TX bytes:28529045 (27.2 MB)

The blue color shows the IP-address (inet addr).
The brown color shows the MAC-address (HWaddr). Every network card in this world has a unique hardware (mac) address.

You can also see your IP-address on the web. Visit or

How do I restart my network connection?

$ sudo /etc/init.d/networking restart

If you have a DHCP connection… over cable modem or similar, renew your IP-address by typing
$ sudo dhclient eth0
This command is handy when your network has been temporarily down. Renew your IP-address and connection.
Replace eth0 with correct device name.

Can I run KVM (hardware virtualization) on this machine?
See question 1.4:
Study also the virtualization guides here…
How do I produce a complete hardware report?
$ lshw
You can also create a HTML report etc. Check
$ lshw –help
An example:
$ lshw -html > report1.html
——-Study also GNOME’s System -> Administration -> Hardware Information dialog
and http://hardinfo.berlio’s product. It is a good system info an benchmarking tool with reporting option. It’s in Synaptic.
——-The script can help you to
debug sound problems.
It will detect your sound hardware and uploads the data to the for others to
Get the script
$ wget
And run it + upload the data to
$ bash

Here is info of my sound hardware:

See also:
$ lspci
$ lsusb
$ lshal


System configuration issues

What do you call this Ubuntu release?
$ lsb_release -a
Distributor ID: Ubuntu
Description: Ubuntu 7.10
Release: 7.10
Codename: gutsy
What’s the version of this Linux kernel?
$ uname -r
or type
$ uname -a
What are the kernel parameters (given at boot)?
$ cat /proc/cmdline
root=UUID=9887d5b7-62ec-4f07-beaf-82816f6d27fd ro quiet splashSee also /boot/grub/menu.lst file. Look for the kernel line.
Where are the display, mouse and keyboard settings?
These settings are saved in the xorg.conf file in /etc/X11/ directory. Type it out.
$ cat /etc/X11/xorg.confThe most important sections are “Device”, “Screen” and “ServerLayout”.
Luckily the X (Unix/Linux’ display system) is highly sophisticated and almost automatic. There is no need to meddle with the /etc/X11/xorg.conf file anymore in Xorg v7.3 (trust me ;-).
How do I know if direct rendering is activated?
Direct rendering means that the display system is using OpenGL and the graphics card with accelerated speed to render text, 2D/3D images and windows. Games and Compiz 3D desktop need direct rendering to work properly.First of all you need to install a proper driver for your graphic card. Study step 5) of this guide.

Then check whether direct rendering is activated (it should say; direct rendering: Yes).
$ glxinfo | grep -i direct
direct rendering: YesTest the performance with glxgears program
$ glxgears
58696 frames in 5.0 seconds = 11739.064 FPS
58458 frames in 5.0 seconds = 11687.287 FPS

This new NVIDIA 8800 card paints graphics really fast.
Numbers over 4000 FPS are pretty good thou.

How do I manually reconfigure the display, mouse and keyboard settings?
The mouse, video and keyboard settings are saved in /etc/X11/xorg.conf file.
You can re-configure it.
First, stop the graphical display manager (gdm, kdm, any ?dm). This will terminate the X.
$ sudo /etc/init.d/?dm stopAnd rebuild the xorg.conf file.
$ sudo dpkg-reconfigure xserver-xorgRestart the graphical display manager. This will restart the X.
$ sudo /etc/init.d/?dm restart

NVIDIA provides its own tools such as nvidia-installer, nvidia-settings and nvidia-xconfig.
ATI ‘s driver comes with aticonfig command line tool.

Study also the Ubuntu’s binary driver howto…

The graphical display will not start.
How do I configure a basic graphical display so I can get to the desktop?
Vesa driver is always present in Ubuntu and all graphic cards can be set to a Vesa-mode.First, edit your /etc/X11/xorg.conf manually
$ sudo nano /etc/X11/xorg.conf
$ sudo vim /etc/X11/xorg.confFind and edit Section “Device” and set the Driver to “vesa”.
Section “Device”

Driver “vesa”

It will give you a basic 800×600 resolution display.
Read the above advice how to restart the graphical display manager.

How do I test performance (speed) of this graphic card?
$ glxgears
28658 frames in 5.0 seconds = 5731.508 FPS (frames per second)
26464 frames in 5.0 seconds = 5292.711 FPS
Numbers over 4000 FPS are pretty good.
How do I switch to a text console?
Unix and linux are unique in that they have several plain text mode consoles.
Press CNTR + ALT + F1 (or any F1…F6 ) to switch to a sepesific console number.
Press ALT + F7 (or one of F7 … F9) to switch back to the graphical UI.Study also Xnest:
$ sudo apt-get install xnest
$ gdmflexiserver --xnest
How do I set up screen resolution of text consoles?
You can add a “vga=” parameter to the end of kernel line in your GRUB menu.lst file.
Edit your menu.lst.
$ sudo gedit /boot/grub/menu.lstThen locate your kernel line and add the parameter as shown in this exampletitle Ubuntu Gutsy Beta , kernel 2.6.22-12-generic /dev/sda6
root (hd0,5)
kernel /boot/vmlinuz-2.6.22-12-generic root=UUID=9887d5b7-62ec-4f07-beaf-82816f6d27fd ro vga=794
initrd /boot/initrd.img-2.6.22-12-generic

Table of valid vga (vesa) codes

640×480 800×600 1024×768 1280×1024 1600×1200 Ask user at boot
8 bits vga=769 vga=771 vga=773 vga=775 vga=796 vga=ask
16 bits vga=785 vga=788 vga=791 vga=794 vga=798 vga=ask
32 bits vga=786 vga=789 vga=792 vga=795 vga=799 vga=ask
How do I list and set the default sound card?
List the detected sound cards
$ asoundconf list
Names of available sound cards:
Nvidia/Realtek mobo internalSet the default sound card
$ asoundconf set-default-card Audigy2Note: You can disable motherboard internal sound cards in BIOS (if you have several cards and the internal disturbs).
EDIT: Multiple sound cards are not a problem anymore in the new PulseAudio audio system. All major Linux distributions are now moving to PulseAudio tools: pavucontrol, paman, pa*.

See also:
$ cat /proc/asound/cards
$ lspci

How do I check mixer and volume settings?
$ alsamixer
$ gnome-volume-control
Or double-click the loudspeaker icon on the notification area (toolbar).
Normally you need to open at least Master and PCM channels to get sound output.
What disk drives / partitions are to be mounted at system start?
Study the fstab file in /etc directory.
$ cat /etc/fstab
What are the correct disk IDs (UUIDs) ?
UUID is an unique identificator that is generated when you format a partition. It is often used in place of disk LABEL.
UUIDs can easily get wrong in the /etc/fstab file, especially when you install several Linux-distributions and format some of the partitions.
UUID mismatch in the /etc/fstab causes mount failures.Use the vol_id command to report correct UUID for a partition.
$ sudo vol_id /dev/xxx
An example:
$ sudo vol_id /dev/sda1List UUIDs for all drives / partitions ( cat /proc/partitions ):
$ for P in $( cat /proc/partitions | awk ‘/[0-9]$/ {print $4 }’ ); do D=/dev/$P; echo -n “$D UUID=”; sudo vol_id –uuid $D; done

/dev/sda1 UUID=404ffdf8-3643-4097-83af-429460a31a8e
/dev/sda2 UUID=6d053143-6cd5-45d5-88a8-c8931a2aca67
/dev/sdb6 UUID=bc58978d-4dfc-4e07-9cc7-0a64450717af

Now compare the UUIDs in the /etc/fstab to output from the above command. The IDs must match !

Be also careful when you copy GRUB menu lines from another system or from an old file. Here is a typical menu entry of a /boot/grub/menu.lst file.
title Ubuntu hardy (development branch)
root (hd1,1)
kernel /boot/vmlinuz-2.6.24-2-generic root=UUID=b2861f09-e378-4988-9edd-9ef2438da482 ro
initrd /boot/initrd.img-2.6.24-2-generic

The root partition is identified by its UUID. If it is incorrect the system will not boot.

Study also output of:
$ ls -l /dev/disk/by-uuid/

What volumes (partitions) are currently mounted?
$ mount
/dev/sda6 on / type ext3 (rw,errors=remount-ro) <— this is your root filesystem “/”.
/proc on /proc type proc (rw,noexec,nosuid,nodev)
/sys on /sys type sysfs (rw,noexec,nosuid,nodev)
/dev/sdb1 on /media/sdb1 type ext3 (rw)
How to remount the partitions after I modified /etc/fstab?
$ sudo mount -a
$ sudo mount -a -o remountStudy also:
How to mount NTFS and FAT partitions…
How do I check and activate swap?

Report the current swap usage.
$ swapon -s
$ cat /proc/swapsYou can create swap on a big disk file or a partition.
$ man mkswap
$ man swapon
Where is my boot menu?
You GRUB boot menu is saved in /boot/grub/menu.lst
$ cat /boot/grub/menu.lstYou can temporarily change the GRUB boot menu.
Press the ‘e’ key when in the GRUB boot menu (the first screen after power on). Move the cursor to a correct line an press ‘e’ again to edit it. These changes disappear after restart. You must edit the /boot/grub/menu.lst file to make the changes permanent.
What kernel modules (and drives) are currently loaded?
$ lsmod
How do I load / remove a module or driver?
$ sudo rmmod modulename # remove
$ sudo modprobe -r modulename # remove
$ sudo modprobe modulename # load a moduleSee also:
$ pcimodules
Where do the modules and drivers come from?
Open source drivers come with the Linux kernel. See
$ ls -l /lib/modules/$(uname -r)/kernel/drivers/
$ ls -l /lib/modules/$(uname -r)/kernel/drivers/*/*.koClosed source (restricted) drivers come from the respective hardware vendors or from Canonical‘s (Ubuntu head quarter’s) servers and repositories.
Where is the kernel source?
$ ls -l /lib/modules/$(uname -r)/build
/lib/modules/2.6.22-14-generic/build -> /usr/src/linux-headers-2.6.22-14-genericThe source directory should have a symbolic link (ln -s) to /usr/src/.
The Linux source package is:
$ apt-cache show linux-headers-$(uname -r)
How do I know if the firewall is up and running?
Firewall in Linux is called iptables…
Iptables is also the name of a command line tool to view and change the internal firewall rules. Iptables command line tool is nice, but a GUI firewall front-end is easier to use.List the current firewall rules
$ sudo iptables -LAn empty rule set will look like this…
If the rules list is empty then rush and install the Firestarter GUI… ( It’s in Synaptic. Search for package “firestarter” )
Then start Firestarter from the System -> Administration menu. It will generate some default iptables rules to protect your web life.
See also: iptables-restore and iptables-save commands.

Ubuntu’s iptables howto….

Important! Read also the firewall section of this document…

How do I check who is/was logged on?
last, lastb – shows listing of last logged in users.
$ last
$ last -xHow do I report the system uptime?
uptime – Tells how long the system has been running.
$ uptime
I forgot my password. How to fix it?
How do I edit a system file? (only root user or sudo can edit system files)
$ sudo gedit afileOn a plain text console,
$ sudo nano afile
$ sudo vim afile

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