CentOS 6 to CentOS 7: Upgrade of my Desktop

Deciding that the best way to learn a system is to use it, I recently decided to move my primary Desktop system at work from CentOS6 to CentOS7. This is the story of that upgrade.

Running the Upgrade Tool

So, after some planning and system prep work, I ran the CentOS upgrade tool. This caused me many false starts - including the fact that my system had been Oracle Linux at one point in it's life, and the CentOS upgrade tool didn't like the OEL packages. So I tried to change the offending OEL packages to CentOS ones, which included the sterling idea of removing glibc from my system's rpm database [Hint: don't do this, or if you really feel that you have to, do remember to type "--justdb" in the command, unlike me who knew to type it but left it off the actual command I executed, and thus accidentally removed glibc from a running system, which was not the best scenario]). I did discover wonderful commands such as "yum distro-sync" which will prove invaluable in years to come, but was a lot of heartache in between.

After such small starter issues, I got the upgrade tool to recognise my system fully, so I ran the prechecks and then ran the actual upgrade itself... at which point it outright failed. The upgrade tool refused to upgrade, since I had Gnome installed. So, I "yum remove"d GNOME (as per Red Hat KB) and continued.

After The Fall, Comes a Reinstall

So, the upgrade tool dutifully upgraded my system - and left me without a working GDM login screen (which I couldn't fix, since I don't know the inner murky depths of systemd), broken /var/log/ output files, and quite a few more elements that should have worked on a cleanly-installed system.  So, after all of the above travails, I decided to simply reinstall. Noone else on the internet appeared to have my gdm problem, except two others (on Fedora) who also reinstalled after their failed upgrades. It would have saved me many, many hours if I had just done this in the first place.

...Except Now I can't Reinstall Either

So I booted the Install DVD, ran the installer... but this then failed to install on my system.

I hit the issue "you haven't selected a bootable stage 1 partition" in the disk partitioning installer section -- the installer decided that my hard drive needed to be GPT instead of MBR format, but instead of telling me this, it decided to hit me with unrelated errors telling me I had did not have a boot partition (when I did).

See here for resolution for this issue: http://fedoraproject.org/wiki/Common_F20_bugs#UEFI_install_to_ms-dos_.28.27MBR.27.29_labelled_disk_fails_with_unclear_errors

So I had to convert my disk to GPT and re-run the installer. It ran easily after that, it was mostly a boring straightforward affair that someone else can blog about.

I saw someone else at work also hit this issue, but they simply blew the whole disk away and let the installer do it's own thing -- I wanted to do something silly, like keep the existing data I had on the drives without a reformat (yes, I had backups elsewhere, but that's not the point).

So, I finally get to Reinstall... and GNOME needs a lot of help

So much help, that  I posted about it here.

On CentOS6, I used Gnome2 as my primary desktop interface, so Gnome3 seemed like a logical thing to move to. With a decent amount of research and effort, I actually quite like it now. My link shows what I changed to make it feel like home.

Other System Stuff

# Install EPEL
yum install -y epel-release --enablerepo=extras
yum upgrade -y epel-release
# or manually:
yum install http://fedora.mirror.uber.com.au/epel/7/x86_64/e/epel-release-7-1.noarch.rpm


# Install ElRepo (for NVidia kernel)
yum install http://www.elrepo.org/elrepo-release-7.0-2.el7.elrepo.noarch.rpm

# Install Chrome (as per http://www.if-not-true-then-false.com/2010/install-google-chrome-with-yum-on-fedora-red-hat-rhel/):
cat << EOF > /etc/yum.repos.d/google-chrome.repo
[google-chrome]
name=google-chrome - \$basearch
baseurl=http://dl.google.com/linux/chrome/rpm/stable/\$basearch
enabled=1
gpgcheck=1
gpgkey=https://dl-ssl.google.com/linux/linux_signing_key.pub
EOF
yum install google-chrome-stable


# Install "nux desktop" for vlc
yum install http://li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-1.el7.nux.noarch.rpm

# Install vlc from Nux
yum install -y vlc


# Disable "nux desktop" from being auto-enabled
cd /etc/yum.repos.d/
sed -i.orig 's/enabled=1/enabled=0/' nux-dextop.repo



Nvidia Drivers - The Easy Way!

# Install ElRepo repo above
yum install nvidia-x11-drv nvidia-detect kmod-nvidia
reboot