SCIENTIFIC.DK^™ develops and coordinates Bio. & IT. projects

UNDER DEVELOPMENT just NOW: 10th of February to 10th of march and then updating.

To prevent problems and ease all rescues, we suggest:

• the two parallel Linux hard disks - one for experimenting eg. programs or added functionality - and one clean & ever well-working system that is updated later when fully tested on the experimental partition.
• the separate /home partition from the point of installation
• Backup of the boot sector and the package list (as it will be saved in your home directory, you can recover easily your experimenting hard disk)

Backup of the boot sector and the package list for MAYBE later rescue.
Start a terminal  as seen in the button under OBS and copy this bold text line by line followed by Enter:

sudo dpkg --get-selections > packagelist.txt #(<-that is backup of your program package list)
sudo dd if=/dev/hda of=bootsector.img bs=512 count=1 #(<-that is backup of your boot sector)
                              #(and MAYBE later rescue:)
sudo dpkg --set-selections < packagelist.txt#(<-write this only if you'll reinstall packages)
sudo dd if=bootsector.img of=/dev/hda #(<-write this only if you need your boot sector recovered)

You can even install the same programs to another computer - copy the file packagelist.txt
from your own home directory to the other computers home directory and write the rescue bold text in a new terminal. (This works if your bootsector is in your first IDE-partition - if you have SCSI or SATA hard disks replace /dev/hda with /dev/sda).

Rescue dependencies.
Especially using .rpm files you may have got some serious problems to install and upgrade your sistem. Then you often got bad dependencies and a soft cure is: sudo apt-get install --fix-missing
Also sudo dpkg --configure -a is helpfull after understanding the man pages ;-) and so needed if you do not take any changes when you even force the recovery using: sudo apt-get -f install

Rescue the graphic mode:
sudo dpkg-reconfigure xserver.xorg # principal all programs that are changed after installation can be reconfigured this way.
sudo dpkg-reconfigure gdm # reloading GNOME Display Manager configuration - and erase your own.
(eg. sudo dpkg-reconfigure locales #when you'll choose languages).
Sometime you get some graphic, but no desktop. Then you can reinstall gnome (save every open files before this and write the following 2 lines:)
press Crtl+Alt+<-  followed by writing in a terminal*:
sudo rm -rf .gnome* xstart  #and restart the computer or with KDE sudo rm -rf .KDE* xstart
If you want to reset the Gnome settings to your working version of your inserted & mounted the security hard disk** after the mounting you can write in a terminal:
sudo cp /media/hda1/~/.gnome* /~/.gnome*

Rescue network set-up
Provided you inserted & mounted the security hard disk**, the easy way to rescue is to copy the network set-up from this well-working other hard disk by writing in a terminal:
sudo cp /media/hda1/etc/network/interfaces /etc/network/interfaces if you have mounted the other drive in the mount-point /media/hda1/. If that is not enough copy the whole directory:
sudo cp /media/hda1/etc/network/* /etc/network/

If you got a Nvidia graphic controller do find help to the driver
/usr/bin/nvidia-settings -h
and  load the configuration file, send the values specified therein to the X-server, and exit:
sudo /usr/bin/nvidia-settings -l

Optimizing installation functionality
Try with care to solve possible dependency problems:
dpkg --configure --pending
apt-get -f install
apt-get install ubuntu-desktop
OR:
sudo /etc/init.d/postfix stop

Logfiles and debugging
If you got problems under boot write in a terminal*
dmesg

You can find the daily log of the system writing in a terminal*
sudo gedit /var/log/syslog

To find which processes that are running write in a terminal
fuser to see opened file handles for a specific file or list
of files in a directory (options see man fuser) E.g. sudo fuser /dev/*
and look at:
top and you can kill the processes pressing k followed by th PID numberVery useful to find out what
process/processes have opened file handles for a specific file or list
of files in a directory.

Rescue data from a partition of your harddisk
If you have a hard disk drive, or a drive partition that is failing, or if you want to copy data from one partition to another (don’t we all, at some time or the other?), then ddrescue comes to the rescue!
In case parts of the partition you are trying to rescue data from are corrupt, then ddrescue (unlike dd) skips over it and gets out all the data that is uncorrupted!

Install ddrescue using
$sudo apt-get install ddrescue

Make sure you have a partition with more disk space that the entire partition you are trying to retrieve data from. Yes, that includes occupied AND free space on the partition you are trying to retrieve data from.

Rescue data using:
$dd_rescue /dev/hda1 /some/dir/drive-backup.img
Where you might have to replace /dev/hda1 with the partition you are trying to rescue data from, and /some/dir/ should have more free space than the entire /dev/hda1 partition.

This creates a drive image. You can mount it as a loop device. Do the following to do just that:

sudo touch /dev/loop1
sudo losetup /dev/loop1 /some/dir/drive-backup.img
–If you get an ioctl error, run “$sudo modprobe loop”, and run the prior command again
sudo mount -t ext3 /dev/loop1 /media/drive-backup
(replace ext3 with the filesystem type of your old partition)

Now browse /dev/loop1 and copy out all your data. If you use an external USB drive to backup the image to, you can take the image with you . Thanks to Dan Martin who posted this at the ubuntu-users mailing list.

Manuals & Documentation:
Some very nice english help pages exist in Ubuntu.

For national languages you'll find a lot of help in Linux communities eg. in Chinese and in Danish and there exist in the Ubuntu community help-pages also in Chinese or in Danish.
But much more exist for Linux and Unix in general as everything is in fundament Unix-oriented: In most Linux distributions you'll find a help manual in the menus (for Gnome og KDE). This is usefull for especially subject oriented search. If you like to search error-messages search the internet (as google) and if you are not on-line search keywords in the Unix manual pages this way.

Start a terminal  as seen in the button under OBS and copy this bold text only:

man -k floppy (then you get a list of commands, which consern floppydesks)
(If you like to format a floppy an want to know how through a terminal do:)
man fdformat (and you get that standard formatting floppies are fdformat /dev/fd0)

Substitude floppy with the keyword of your choice. The man pages can be difficult as no or few examples are given - I guess that useability is why Linux appeared from the powerfull but terminal fixed Unix in 1991.
Dokumentation beside: in a terminal do write in a terminal: 
sudo dmesg #what has happened when you start the computer
sudo lspci # tell you about which PCI controllers recognized
sudo lsusb # outline which USB devices installed
sudo top # note which proc proces are currently running and the log files are found in /var/log/ directory (e.g. /var/log/Xorg.6.log telling you how the screen have succeeded the setup).

For a survey of the ideas of this IT-project go to the example of our present projects

Other technical support is found at:
For that reason we suggest that you step to our other technical support pages at:
http://scientific.dk/IT-support/index.html
http://scientific.dk/IT-support/installation.html
http://scientific.dk/IT-support/optimization.html
http://scientific.dk/IT-support/specialization.html