The Open Telekom Cloud is switching all the flavors of its Elastic Cloud Server offering to the Kernel-based Virtual Machine (KVM) hypervisor. Telekom is replacing the flavors, which are currently still operated on the basis of the Xen hypervisor, with new KVM flavors that are at least equivalent.
KVM instead of Xen: future standard hypervisor in the Open Telekom Cloud
"Overall KVM offers more functionality and stability in cloud operation. Most applications gain noticeably in performance with KVM," says Andreas Falkner, Vice President Open Telekom Cloud. "Overall, KVM better meets the demands of cloud operations. In addition, we are now standardizing our cloud offering, which ensures end-to-end compatibility and reduced complexity for companies.“
KVM has become the de facto standard within the user community. The clear majority uses KVM, many have already switched on their own from Xen to KVM. For companies that continue to use Xen-based flavors on the Open Telekom Cloud, Telekom experts offer support for the switchover. "Switching from Xen to KVM within the Open Telekom Cloud is uncomplicated in most cases. Companies have to shut down corresponding systems and restart them on the new flavor," says Clemens Hardewig, Vice President Open Telekom Cloud Delivery.
Telekom has produced a Migration Guide that explains exactly how this works in detail; both for systems running Linux and for Windows-based machines. It also shows which KVM flavors will replace the Xen flavors, what possible problems there might be with drivers and device names, and how users can keep IP addresses and volumes unchanged if necessary, despite changing flavors.
Users have three months to switch from Xen-based to KVM-based flavors. After that the Xen flavors will be switched off for good. The transition period begins on June 30, 2019. The deadline for the switch is therefore September 30, 2019. In order to avoid failures, all users of flavors with Xen hypervisors must have switched to a KVM equivalent by September 30, 2019 at the latest. If companies have any questions, they can contact Telekom experts at any time on 0800 33 04477 if calling from Germany or 00800 33 04 47 70 for those calling from other countries.
In order to enable customers to continue to provide SAP services, the certified SAP flavors based on the SUSE Linux Enterprise Server are initially excluded from the changeover and are therefore still available in the shop for the time being. The supply of the flavors will ends on 05.03.2021. From April 2020, we will offer SAP exclusively via Managed Services as private deployment. You will be informed about this by us or your personal contact in advance.
You can find an overview of certified SAP flavors using this link.
In addition, the large memory flavor and all GPU flavors are also excluded from the conversion to KVM for the time being. The relevant users will be informed separately when Telekom converts these flavors from Xen to KVM.
An overview of the most important questions about the Xen-KVM migration on the Open Telekom Cloud (FAQ)
Yes, Telekom will replace all Xen-based flavors with KVM flavors. The certified SAP flavors based on the SUSE Linux Enterprise Server, the large memory flavor and all GPU flavors are excluded from this for the time being.
First, the rollout of new Xen machines will be discontinued. These will then no longer be offered in the shop. However, the existing flavor’s Start, Stop, Backup and Restore functions will remain available until they are completely switched off. The transition period is three months and starts on June 30, 2019. The latest date for the switch is September 30, 2019.
The only disadvantage is the process of changing the affected flavors itself, which is unfortunately necessary.
Users have to switch to a KVM-based flavor within the three-month transition period. Otherwise systems with the Xen flavor will be switched off. Before this happens, the Open Telekom Cloud team will inform the users of the flavors concerned several times by e-mail.
That depends on the way companies use Xen-based flavors within the Open Telekom Cloud. There are detailed instructions in the KVM Migration Guide, both for systems running Linux and for Windows-based machines. Telekom also offers telephone support at: 0800 33 04477 for callers based in Germany or 00800 33 04 47 70 for those calling from other countries.
Existing Reserved Upfront packages for certain Xen flavors will continue to run. However, if you want to switch to KVM earlier, you can migrate the packages one to one.
Yes, dedicated hosts are also be part of the migration.
A detailed list of the affected Xen flavors and their KVM equivalents can be found in the Migration Guide for Linux and Windows users and in the following table.