Open Telekom Cloud for Business Customers

KVM instead of Xen: Start of the first phase towards standardization of the hypervisor in the Open Telekom Cloud

by Editorial team

The Open Telekom Cloud is starting the first phase towards standardization of the hypervisor. In future, we will rely on the Kernel-Based Virtual Machine Hypervisor (KVM). In this connection, in the first phase, the General Purpose Flavors (c1, c2, m1, s1) based on the Xen Hypervisor will be discontinued on December 31, 2019.

Bluish digital representation of an equalizer
Changing virtualization layer: All Open Telekom Cloud flavors will in future be based on KVM hypervisors. (Image: iStock/Fos4o)

“Overall, KVM offers more functionality and stability in the cloud area. Most applications experience a noticeable increase in performance thanks to KVM,” said Andreas Falkner, Vice President Open Telekom Cloud. “Overall, KVM is better suited to meet the requirements of a cloud business. In addition, we are now also standardizing our cloud offering, which will ensure consistent compatibility and reduced complexity for companies.”

Telekom experts support in switching from Xen to KVM

In the meantime, KVM has developed into a de facto standard within the user community. A significant majority uses KVM, and many have voluntarily switched from Xen to KVM in the past. During the switch, Telekom experts offer support to companies that are still using Xen-based flavors on the Open Telekom Cloud. “Switching from Xen to KVM within the Open Telekom Cloud is simple in most cases. Companies have to shut down corresponding systems and restart them with the new flavor,” said Clemens Hardewig, Vice President Open Telekom Cloud Delivery.

Telekom has put together a detailed Migration Guide outlining how exactly this works; both for systems operating on Linux and for Windows-based machines. In particular, this highlights the KVM flavors that are replacing the Xen flavors, the possible problems that might arise with drivers and device names, and how users can, if necessary, keep their IP addresses and volumes unchanged despite switching flavor.

It is still possible to book Xen-based flavors until October 31, 2019. The deadline originally set for September 30, 2019 has been extended by four weeks. After this time, it will no longer be possible to book Xen-based General Purpose Flavors (c1, c2, m1, s1).  On December 31, 2019, the above-mentioned General Purpose Flavors based on the Xen hypervisor will be deactivated.

To avoid downtimes, anyone using flavors with the Xen hypervisor, must have switched over to a KVM equivalent by December 31, 2019 at the latest. Companies can direct any questions to the Telekom experts at any time by calling 0391 5976 2433 for callers from Germany or +49 391 5976 2433 for callers from different countries.

Xen flavor for SAP systems, disk-intensive, large memory, GPU and high-performance flavors will initially be excluded from the conversion

To provide customers with continuity in the provision of SAP services, the certified SAP flavors (e1, e2, h1) will initially be excluded from the conversion and can therefore still be ordered for the time being. Provision of the flavors will end in the second quarter of 2022, which is why reserved models with a term of 36 months were still available until the second quarter of 2019. Shorter terms and elastic models are available accordingly to the end of the remaining term.

At the same time, we are endeavoring to certify KVM flavors for SAP. Telekom assumes that the first certified flavors will be available in 2020. As soon as this is the case, Telekom will give notification of their availability.  

In addition, the disk-intensive flavors, the large memory flavor, all GPU flavors and the high-performance flavors will initially be excluded from conversion to KVM. A schedule for further XEN-based flavors (d1, g1, g2) identified as exceptions has not yet been defined. Telekom will provide information about this.

Summary of frequently asked questions about Xen-KVM migration on the Open Telekom Cloud (FAQ)

Do companies that are currently using Xen-based flavors of the Open Telekom Cloud have to switch?

Yes, Telekom will replace all General Purpose Xen-based flavors with KVM flavors. This will initially exclude the certified SAP flavors (e1, e2, h1), disk-intensive flavors (d1), large memory flavor, all GPU flavors and the high-performance flavors.

When will Xen-based flavors be deactivated in the Open Telekom Cloud?

Initially, the rollout of new Xen machines will cease. These will no longer be offered in the shop from October 31, 2019. However, the start, stop, backup and restore functions for existing flavors will remain available until complete deactivation. The latest date for the switch is December 31, 2019. On this date, the above-mentioned General Purpose Flavors (c1, c1, m1, s1) based on the Xen hypervisor will be deactivated.

What are the drawbacks of the switch for companies?

The only drawback is the switching process itself for the flavors concerned, which is unfortunately necessary.

What do companies that use Xen-based flavors in the Open Telekom Cloud need to know?

Users must switch to a KVM-based flavor by December 31, 2019. Otherwise, systems with Xen flavors will be deactivated. Before this happens, the Open Telekom Cloud team will inform users of the tenants concerned by email.

How can companies switch from Xen-based flavors to a KVM-based flavors?

This depends on the manner in which the companies use Xen-based flavors within the Open Telekom Cloud. The KVM Migration Guide provides detailed instructions, both for Linux and for Windows users. In addition, Telekom offers telephone support on: 0391 5976 2433  for callers from Germany or +49 391 5976 2433 for callers from other countries.

What will happen to the reserved upfront packages?

Existing reserved upfront packages for certain Xen flavors will continue to run. However, anyone who wishes to switch to KVM sooner can have the packages migrated one to one.  

Are dedicated host flavors also affected?

Yes, dedicated hosts are also involved in the switch.

Exactly which flavors in the Open Telekom Cloud are affected?

Users can find a detailed list of the affected Xen flavors together with their KVM equivalent in the migration guide for Linux or Windows users and in the following table. 























































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