Install Another Distribution

From openSUSE

When you must install a distro other than the one you actually use, such as the SUSE beta, this is a very handy way to do it:

Advance Preparation

• In advance, it is necessary to have one or two large partitions free (5 to 10Gb).
• It is also very useful (but not mandatory) to have a data partition to receive all your own data. This is not your home, only your important data.

User ID Change

When a user installs his own computer, usually he sets up the accounts the same, so all the user IDs of his family are always the same.

But, starting I don't know when and I don't know why, the user IDs that used to start at 501 began to start at 1000 (my Mandrake 10.1).

So, to be able to read my old files, I was obliged to change this to my old user ID.

And now SUSE did it :-(. My new account is user ID 1000! I can't read the old data.

It's a problem because changing the user ID is not simple (many secondary problems can arise).

The best way is probably to go root, delete the newly created account and recreate it with the required user ID before doing too much work on it :-(. Another way is to carefully edit file /etc/passwd and change the new ID in the third field to your old ID. Make a copy of the /etc/passwd file before doing this. Also change your home directory and files under it with chown -r youroldaccount /home/yourhomedirectory

When Installing

• Always use the "failsafe" option in the install menu (the boot menu). This slows you down a bit, but can install in quite any condition. There is often a dma problem with some disks or the CD.

• Install the new distro in the extra partition. Don't bother to fine tune the partitioning system now. Only partition is enough. For example, /dev/hda8.

• Have the boot loader (grub or lilo) write itself on the first sector of the root partition. YaST has a special menu entry for this.

• After the first CD is installed, SUSE needs a reboot. Of course, the boot loader is not installed on the MBR so this is the old system that boots.

lilo

• Edit /etc/lilo.conf if the old distro uses lilo and add two lines as root:

other=/dev/hda8
 label="SUSE 10.0"

• Save, then validate, with lilo (that is, run the command 'lilo' to update). If you made a typo, lilo complains. If not, all goes well.

grub

For grub, add this to the /boot/grub/menu.lst file:

title SUSE 10.0
    rootnoverify(hd0,7)
    chainloader +1

The rootnoverify clause is different from the standard linux /dev/hda1 in that it counts from zero: hda8 is (hd0,7) and hdb1 is hd(1,0).

• Just restart your computer (no update command is needed for grub).

That's all. Of course, set up the /dev for your config.

After Rebooting

At boot, you will see another entry in the old menu (suse) If you choose "SUSE 10.0", you will be sent to the new SUSE boot menu.

Select it and things should work.

You can fine-tune the above by adding an entry in the SUSE boot menu for your old system, just in case :-).

Then all you have to do is mount your data partition in any /media or /mnt and link your data directories to your new home :-).