Change cloud server configuration

Last update: October 05 2026Open in Markdown

You can change a cloud server's configuration and amount of resources:

• select a different lineup and fixed configuration (except for the GPU lineup);
• change a fixed configuration to a custom configuration (except for the GPU lineup);
• change the amount of resources in a fixed or custom configuration — vCPU, RAM, local disk size;
• change a custom configuration to a fixed one;
• configure dedicated cores for a cloud server, enable Hyper-Threading (SMT), and enable mandatory placement of resources on a single NUMA node in the configuration.

A cloud server configuration with a local disk cannot be changed to a configuration without a local disk and vice versa.

You can add GPUs to custom configuration servers.

When changing the configuration, all data on the cloud server is preserved.

Change server configuration

carefully

During the configuration change, the cloud server will be unavailable.

Control panel

1. In the Control panel, in the top menu, click Products and select Cloud servers.

2. Go to the server page → Configuration tab.

3. Click Change configuration.

4. In the Configuration block, select a new configuration. If you need to add a GPU to the cloud server, select the GPU line.

5. Optional: you can adjust the configuration if the cloud server is created in the ru-6 multi-zone pool segment or the ru-3b, ru-7a, and ru-7b pool segments:

   5.1. Expand the block with the description of configuration settings.

   5.2. Optional: select the processor manufacturer. Choosing a manufacturer is not available in all pools.

   5.3. Optional: if you want the cloud server's vCPUs to be assigned dedicated physical CPU cores, select the Dedicated cores checkbox. For more information, see the Dedicated cores instructions. If the cloud server has dedicated cores and you need to disable them, uncheck the Dedicated cores checkbox. If the checkbox is unavailable, dedicated cores cannot be disabled.

   5.4. Optional: if the cloud server has dedicated cores and you want to enable Hyper-Threading, select the Hyper-Threading (SMT) checkbox. To disable hyper-threading, uncheck the Hyper-Threading (SMT) checkbox.

   5.5. Optional: if the cloud server has dedicated cores and you want to place CPU resources on a single NUMA node, select the Mandatory placement on a single NUMA node checkbox. To avoid placing cloud server resources on a single NUMA node, uncheck the Mandatory placement on a single NUMA node checkbox. If the cloud server resources cannot be placed on a single node, the changed configuration will not be applied. For more information, see the Placement on a single NUMA node subsection of the Dedicated cores instructions.

6. Specify the required amount of resources.

7. Click Save and reboot.

8. If you have not changed the configuration and only changed the Hyper-Threading (SMT) setting in step 5.4, perform a hard reboot.

OpenStack CLI

1. Open the OpenStack CLI.

2. Change the cloud server configuration:

   openstack server resize --flavor <flavor> <server>

   Specify:

   • <flavor> — flavor ID or name. Flavors correspond to cloud server configurations and determine the number of vCPUs, RAM, and server local disk size. You can use fixed configuration flavors or create a flavor. You can view the list of flavors using the openstack flavor list command or in the Fixed configuration flavor list across all pools table;
   • <server> — server ID or name. You can view the list of servers using the openstack server list command.

3. Optional: if the cloud server flavor supports dedicated cores, you can configure Hyper-Threading (SMT) or mandatory placement of resources on a single NUMA node:

   openstack server set \
       --property x_cloud_smt_enabled=<enable_value>
       --property x_cloud_numa_nodes=1
       <server>

   Specify:

   • --property x_cloud_smt_enabled=<enable_value> — Hyper-Threading (SMT) setting. In the <enable_value> parameter, specify one of the following values:
     • false — disable Hyper-Threading (SMT);
     • true — enable Hyper-Threading (SMT);
   • --property x_cloud_numa_nodes=1 — placement of resources on a single NUMA node. If the cloud server resources cannot be placed on a single node, the changed configuration will not be applied. For more information, see the Placement on a single NUMA node subsection of the Dedicated cores instructions;
   • <server> — server ID or name. You can view the list of servers using the openstack server list command.

4. If you changed the Hyper-Threading setting in step 3, perform a hard reboot.