Dedicated Core Servers

Dedicated Core Servers that you create in the DCD are provisioned and hosted in one of IONOS' physical data centers. Dedicated Core Servers behave exactly like physical servers. They can be configured and managed with your choice of the operating system. For more information, see Configure a Dedicated Core Server.

Boot options: For each server, you can select to boot from a virtual CD-ROM/DVD drive or a storage device (HDD or SSD) using any operating system on the platform. The only requirement is the use of KVM VirtIO drivers. IONOS provides a number of ready-to-boot images with multiple versions of Microsoft Windows and different Linux distributions, including Red Hat Enterprise Linux.

Availability Zones

Secure your data, enhance reliability, and set up high-availability scenarios by deploying your Dedicated Core Servers and storage devices across multiple Availability Zones.

Assigning different Availability Zones ensures that servers or storage devices reside on separate physical resources at IONOS.

For example, a server or a storage device assigned to Availability Zone 1 resides on a different resource than a server or storage device assigned to Availability Zone 2.

You have the following Availability Zone options:

• Zone 1

• Zone 2

• A - Auto (default; our system automatically assigns an Availability Zone upon provisioning)

Live Vertical Scaling (LVS)

If the capacity of your Virtual Data Center no longer matches your requirements, you can still increase or decrease your resources after provisioning. Upscaling resources allows you to change the resources of a Dedicated Core Server without restarting it, permitting you to add RAM or NICs ("hot plug") to it while it is running. This change allows you to react to peak loads quickly without compromising performance.

Warning: RAM hotplugging for a VM is automatically disabled when the RAM size exceeds 240 GB. This leads to the VM restarting every time the RAM is increased beyond this limit, disabling live vertical scaling.

After uploading, you can define the properties of your images before applying them to new storage volumes. The settings must be supported by the image, otherwise, they will not work as expected. After provisioning, you can change the settings directly on the storage device, which will require a restart of the server.

The types of resources that you can scale without rebooting will depend on the operating system of your Virtual Machines (VMs). Since kernel 2.6.25, Linux has LVO modules installed by default, but you may have to activate them manually depending on the derivative. VirtIO drivers are optimized for virtual environments and provide direct access to underlying hardware.

For IONOS images, the supported properties are already preset. Without restarting the Dedicated Core Server, its resources can be scaled as follows:

• Upscaling: CPU, RAM, NICs, storage volumes

• Downscaling: NICs, storage volumes

Scaling up is the increase or speed up of a component to handle a larger load. The goal is to increase the number of resources that support an application to achieve or maintain accurate performance. Scaling down means reducing system resources, irrespective of whether you have used the scaling-up approach. Without restarting the Dedicated Core Server, only upscaling is possible.

Limitations

CPU Types: Dedicated Core Server configurations are subject to the following limitations, by CPU type:

AMD CPU

Components	Minimum	Maximum
Cores	1 core	62 cores
RAM	0,25 GB RAM	230 GB RAM*
NICs and storage	0 PCI connectors	24 PCI connectors
CD-ROM	0 CD-ROMs	2 CD-ROMs

Intel® CPU

Components	Minimum	Maximum
Cores	1 core	51 cores
RAM	0,25 GB RAM	230 GB RAM*
NICs and storage	0 PCI connectors	24 PCI connectors
CD-ROM	0 CD-ROMs	2 CD-ROMs

Note: Additional RAM sizes are available on request. To increase the RAM size, contact your sales representative or IONOS Cloud Support.

A single Intel® physical core with Hyper-Threading Technology is exposed to the operating system of your Dedicated Core Server as two distinct "logical cores", which process separate threads.

RAM Sizes: Because the working memory (RAM) size cannot be processed during the initial configuration, newly provisioned servers with more than 8 GB of RAM may not start successfully when created from IONOS Windows images.

Live Vertical Scaling: Linux supports the entire scope of IONOS Live Vertical Scaling, whereas Windows is limited to CPU scaling. Furthermore, it is not possible to use LVS to reduce storage size after provisioning.