Partial upgrade messed my system

Although I am aware of the potential risks of a partial upgrade, due to slow connection I thought I will go ahead with it. I was feeling confident that if things mess up I will be able to handle them. I had installed grep and udev without installing upgraded versions of kmod and pcre.

When I restarted [may be I should not have done that], during boot only the system started throwing errors about grep being unable to find libpcre and kmod not being found. I was able to boot into kdm but my keyboard and touchpad were not working. The root of the problem is still unknown; but I thought of trying installing pcre and kmod. However, to install I had to get to the command prompt at least.

So, I created a Gentoo boot disk using my flash drive and chrooted into my system. I connect using 3G USB dongle and from the chrooted environment the mode was not switched. So, I had to get packages downloaded separately and then install them through the chrooted environment. I should have installed the same version as in my system's pacman database; but I installed the latest one. With that I fixed the boot problems and my keyboard was working but it broke a few other things and kdm did not work any more. When I booted now, it took me to the command line. I reinstalled kdebase-workspace; yet the issue persisted. To make things worse, I found that emacs and irssi were also not working. So, I couldn't get to any IRC channel to ask for help. The only good thing that happened was I was able to get to a command line. So, I did not have to download packages elsewhere and install it.

 When I connected to the internet from my system and ran pacman -Syu it showed me downloads of around 650 mb. I found that many of those packages like libreoffice and 32-bit libs are not absolute necessity from a repair perspective. So, I decided to download a small subset to get my KDE back. I downloaded

• avahi 
• ca-certificates 
• compositeproto 
• cpio 
• kdelibs 
• kactivities 
• libxrandr 
• xdg-utils 
• qt  
• oxygen-icons 
• kdepimlibs 
• kdepim-runtime 
• libxml2 
• libqalculate  
• libxcomposite 
• libmysqlclient 
• libvorbis 
• libshout 
• sdl_image 
• zvbi 
• vlc

 The list above is a subset of the packages pacman wanted to download for the system upgrade; but at the same time they also form a superset of the packages I believed could cause my KDM issues.This solved my problem and now I am blogging from my revived linux system.


Caution:
Experiments like these should not be undertaken unless
1. You are crazy like me.
2. You have a backup system and have your /home folder on a separate partition so that even if your system can't be fixed, you can install a fresh new system without losing data. [You can also save configurations in /etc.]
3. You have sufficient bandwidth.