Monday, January 30, 2012

Upgrading EOL Ubuntu versions

Upgrading older ubuntu versions is straight forward.

Just upgrade all packages

sudo aptitude update && sudo aptitude safe-upgrade

and the (after a reboot) do a 

sudo do-release-upgrade

This works fine, as long as the origin version is not EOL.
When your server is having a EOL version installed, then you must dig somewhat deeper:

You have to change the source repositories to old-releases (instead of achives as mentioned in many posts/sites)

So you do change sources.list to:

deb dapper main restricted universe multiverse
deb dapper-updates main restricted universe multiverse
deb dapper-security main restricted universe multiverse 
Then you can do the normal steps as mentioned above.
If the do-release-upgrade command is unknown, then you have to install it:

install update-manager-core

If by change you had the profile "ubuntu-desktop" installed, then first remove that one from your installation.

Modified /usr/lib/

#near line 28, add:
import time
# near the line 101-102, just after "tar.close()", add
    print "----- IT IS TIME NOW !-----"
# Note that you can adjust the time (60) by the value in seconds of your choice...
Theses lines should be like :
          # Wait about 1 minute (time to modify update script)
          print "----- IT IS TIME NOW !-----"
          return True
# Note that you must keep the text idented

Run sudo do-release-upgrade

When the script sleeps, you have just 60 seconds to do the next step:
-- Modified /tmp/tmpXXXXXX/prerequists-sources.list and prerequists-sources.dapper.list and changed them to "old-releases" as well.

Then  wait until the script continues running and asks:
"Do you want to modify the sources list?"

Make sure you don't press enter along the way or it skips that question by assuming a "no".) It will say: "WARNING: Failed to read mirror file."

Go fix /etc/apt/sources.list back to the way it used to be now. With "us.archive" instead of "old-releases" (except for the security lines, that should just be "".

Return to the update and say Yes.
The updater will modify /etc/apt/sources.list and replace all the dapper entries with hardy entries and continue updating using the servers.

Thursday, January 26, 2012

Boot Linux Mint via PXE and NFS

Linux Mint is a linux distribution based on Ubuntu, which in turn is based on Debian.

Linux Mint does not use Unity as desktop manager, but instead uses a extended Gnome3 desktop manager with many additions, so it can be used by most peoples.

Naked Unity and Gnome3 desktops are somewhat confusing for normal and experienced users (At least this is how we did see reactions of users)

When you wish to netboot Linux Mint via PXE and NFS you need the following components:

1. A DHCP server which assigns the correct boot options
2. A TFTP server for loading the pxe environment and loading kernel and initrd
3. A NFS server to deliver the normal Mint squashfs

The setup is identical as for net booting ubuntu, you only have to make sure you specify the correct paths.
A typical pxelinux.cfg entry for mint looks like this:

LABEL Linux Mint 12 64-Bit
    kernel mint12-amd64/vmlinuz
    APPEND boot=casper netboot=nfs nfsroot= initrd=mint12-amd64/initrd.lz --

In this case we have:
- On the tftp server we make a subdirectory called linux12-amd64
- In that directory we put the vmlinux and initrd.lz from the ISO image /casper/ directory
- On the NFS server we just expand the content of the mint iso file into /srv/nfs/mint/12-amd64

It should then work just fine