Because of the ‘GHOST’ scare, and the apparent lack of patched RPMs available for glibc for Fedora 19, I decided to bite the bullet and upgrade some VPSs to Fedora 21. However, instead of doing the sane thing (creating a fresh VPS and copying everything over) I decided to throw caution to the wind and upgrade the VPS in situ.

Digital Ocean Control Panel = SCORE!

The thing that makes it bearable on Digital Ocean is that the control panel makes it easy to switch kernels (which would otherwise be grub on a standalone machine).

On the other hand, they don’t appear to have all the kernel version available, which means that a straight ‘upgrade’ needs to be fixed by installing a previous kernel (one which they do have on the drop-down list).

Step 1 : Take a snapshot

(unless you are actually insane).

Step 2 : Step through a helpful script

Check out this script.

However, I went through this step-by step, since running a clean yum after more than a year of bit-rot would be a surprise.

First, note the kernel that’s being run :

# uname -a
Linux d1.platformedia.com 3.9.8-300.fc19.x86_64 #1 SMP Thu Jun 27 19:24:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux

Then have a run through the first (uncontraversial) steps :

yum update
rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-fedora-21-$(uname -i)
yum update yum
yum clean all

Then onto the upgrade proper :

yum --releasever=21 distro-sync 

This threw up a series of niggles…

Step 2a : Fix dependency issues

yum remove perl-PlRPC-0.2020-13.fc19.noarch

Remember to reinstall its dependencies perl-DBI and perl-DBD-MySQL.

Step 2b : yum runs into memory issues

This is a little disheartening, but the VPS is only 512Mb…
So, refusing to give up, shut down running processes :

#service webmin stop
##Stopping Webmin server in /usr/libexec/webmin

service nginx stop
##Redirecting to /bin/systemctl stop nginx.service

service postfix stop
##Redirecting to /bin/systemctl stop postfix.service

Step 2c : yum+presto runs into memory issues

The solution to this was just to repeatedly re-run yum --releasever=21 distro-sync - eventually all the RPMs get downloaded / expanded successfully (about 3 iterations required).

Step 2d : Continue with the script

yum remove firewalld-config-standard 
## Nothing to do (using iptables)

shutdown -h now

Step 3 : Change kernel on control panel

According to script : same as currently running (fc19).

Power On (via the Panel) takes a while…

Step 4 : Change to upgraded kernel on control panel

Ah - but here’s a problem : yum gave us kernel-3.18.5-201.fc21.x86_64, but the Panel only lists a previous version.

Therefore, need to install the previous version so that we can successfully switch to it.

So : Search for most recent one listed on DigitalOcean, by visiting the Koju build site, and going to the 3.18.3-201.fc21 page. There snag the three required RPMs :

k=https://kojipkgs.fedoraproject.org//packages/kernel/3.18.3/201.fc21/x86_64
v=3.18.3-201.fc21.x86_64
yum install ${k}/kernel-${v}.rpm \
${k}/kernel-core-${v}.rpm \
${k}/kernel-modules-${v}.rpm

Fortunately, that works.

shutdown -h now

Step 5 : Change (for real, this time) to the FC21 kernel on the control panel

Power On.

uname -a
## Linux d1.platformedia.com 3.18.3-201.fc21.x86_64 #1 SMP Mon Jan 19 15:59:31 UTC 2015 x86_64 x86_64 x86_64 GNU/LinuxSuccess!!

SUCCESS!

Step 6 : Backtrack over packages that yum complained about

yum install perl-DBI perl-DBD-MySQL

Minor outstanding issue

The Digital Ocean panel still shows ‘Fedora Fedora 19 x64’ in the droplet’s header field (presumably because that’s the image it was originally created from).



Martin Andrews

{Finance, Software, AI} entrepreneur, living in Singapore with my family.



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