The following provides information to help you prepare your site for the Ubuntu upgrade to version 14.04.5 LTS (aka Trusty Tahr).
What to expect
DreamHost's team will contact you via email in advance of the upgrade. A notice will also be visible in the DreamHost Control Panel during the upgrade process.
The time frame of an upgrade can vary from server to server, however the timing ensures that there are several highly trained engineers on hand should any major issues arise. The upgrade itself should take no longer than an hour to complete.
To date in 2018, DreamHost has completed upgrades on its Shared and VPS web servers. New users on all web servers will also be using Trusty by default (Shared, VPS, DreamPress, and Dedicated). DreamHost is now beginning the process of rolling out upgrades for its Shared MySQL servers.
Any services that rely on the availability of your MySQL server (WordPress or any other database-driven websites, applications, and so on) will not be reachable until the upgrade is complete. This will NOT affect cloud or email services.
Grandfathered VPS servers with an admin/sudo user or root SSH keys are considered "unmanaged" and cannot be upgraded as part of DreamHost's roll-out. Please contact support if this applies to you and if you'd like more information on upgrading.
DreamHost MySQL servers will upgrade its MySQL version to 5.6.39 due to the upgrade. This is the only major change.
Web server changes
Gems and Bundler
DreamHost's Ruby environment is changing. The following describes the major version changes and how to make adjustments to your server.
In order to provide the best possible experience and modernize support for Ruby, DreamHost is no longer maintaining system gems. You must use Bundler (if you haven't done so already) to install any gems you may need.
Ruby version change (from 1.8.7 to 1.9.3)
The Ruby version on the server is changing to 1.9.3. If you would like more control over this, DreamHost strongly recommends using RVM.
Perl version change (from 5.14.2 to 5.18.2)
Ubuntu Trusty includes a new version of Perl, 5.18.2.
For more information on updating your version of Perl, visit the following articles:
Python version change (from 2.7.3 to 2.7.6)
Ubuntu Trusty includes a new version of Python, 2.7.6.
For more information on the latest version of Python, visit the following article:
Django version change to 1.6.11
If you previously installed your version of Django using the old django-setup.py install script, you could potentially see errors with your website. Unfortunately, technical support is unable to assist with any older installation errors.
The only recommended way to currently install Django is in a virtualenv.
ffmpeg is no longer included and was replaced with libav. View the following link for further details:
How can I find support?
As always, if you have any questions or concerns, please feel free to contact support.