Moving from CityCloud Gen1 to OpenStack – Part 3

Luc Van Steen City Cloud, Cloud, Cloud Computing, OpenStack Leave a Comment

I’ve been using the new OpenStack environment at City Cloud for some time now, and enjoying the flexibility and scalability of this platform. Time to migrate your servers from the current Gen1 platform to the OpenStack platform.

To get you up to speed in this migration, I’ve compiled some steps to support this move. In my previous posts, I described the process in how to get started and move your data. This post will elaborate on how to switch from City Cloud generation1 to City Cloud OpenStack.

Moving from City Cloud Gen1 to OpenStack, Part1
Moving from City Cloud Gen1 to OpenStack, Part2

Let’s step back for a minute and take a look again on the process.
The following diagram captures the basic steps I follow for moving my generation 1 cloud servers to the OpenStack Platform.


By now your servers have the migrated volumes attached. Next step is to make sure DNS references are correct.
This is not the most complex part if done well, but keep in mind that most issue in IT are DNS related issues.

As with most public facing services, they depend on DNS resolution. After the DNS changes have been identified, it will allow you to ‘flip the switch’ to send production traffic to the new location. Internal DNS also needs to be considered.

When it’s time for the final cutover, make sure you start the migration inside of a maintenance window that has been set with your end users.
Some best practices :

  • Make sure you shut off any crons and/or background processes that modify data and make a final sync.
  • Lowering your TTL for your DNS a few days before to the cutover. This will result in quick DNS updates.
  • Updating your DNS entries to point to the new environment is the point of no return. After you do this, you’ll be taking live traffic on your new cloud environment. As such it is especially important that you do one final test against your cloud setup before you update DNS.

By now you should be ready with the migration. Don’t forget to review any firewall security policies to match your new environment.
Share your experiences, tips,… by posting your comments. Have fun!



Luc Van Steen

Luc Van Steen

Luc is an IT Specialist/consultant for one of the largest IT companies in the world with a main focus on infrastructure and integration. Networking, security, storage, virtualization, Linux, Windows and scripting are some of Luc’s main skills.

Luc is a major article contributor in the City Cloud blog where he covers all sorts of topics, from the latest industry news to tips&tricks for City Cloud users.


flickr photo shared by @lattefarsan under a Creative Commons ( BY-SA ) license