:original_name: cce_10_0463.html

.. _cce_10_0463:

Kata Runtime and Common Runtime
===============================

The most significant difference is that each Kata container (pod) runs on an independent micro-VM, has an independent OS kernel, and is securely isolated at the virtualization layer. With Kata runtime, kernels, compute resources, and networks are isolated between containers to protect pod resources and data from being preempted and stolen by other pods.

CCE Turbo clusters allow you to create workloads using common runtime or Kata runtime as required. The differences between them are as follows.

+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Category                                                                                 | Kata Runtime                                                                                                                                                                                                                                                                                        | Common Runtime                                                         |
+==========================================================================================+=====================================================================================================================================================================================================================================================================================================+========================================================================+
| Node type used to run containers                                                         | Bare-metal server (BMS)                                                                                                                                                                                                                                                                             | VM                                                                     |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container engine                                                                         | containerd                                                                                                                                                                                                                                                                                          | Docker and containerd                                                  |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container runtime                                                                        | Kata                                                                                                                                                                                                                                                                                                | runC                                                                   |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container kernel                                                                         | Exclusive kernel                                                                                                                                                                                                                                                                                    | Sharing the kernel with the host                                       |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container isolation                                                                      | Lightweight VMs                                                                                                                                                                                                                                                                                     | cgroups and namespaces                                                 |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container engine storage driver                                                          | Device Mapper                                                                                                                                                                                                                                                                                       | -  Docker container: OverlayFS2                                        |
|                                                                                          |                                                                                                                                                                                                                                                                                                     | -  containerd container: OverlayFS                                     |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| `Pod overhead <https://kubernetes.io/docs/concepts/scheduling-eviction/pod-overhead/>`__ | Memory: 100 MiB                                                                                                                                                                                                                                                                                     | None                                                                   |
|                                                                                          |                                                                                                                                                                                                                                                                                                     |                                                                        |
|                                                                                          | CPU: 0.1 cores                                                                                                                                                                                                                                                                                      |                                                                        |
|                                                                                          |                                                                                                                                                                                                                                                                                                     |                                                                        |
|                                                                                          | Pod overhead is a feature for accounting for the resources consumed by the pod infrastructure on top of the container requests and limits. For example, if **limits.cpu** is set to 0.5 cores and **limits.memory** to 256 MiB for a pod, the pod will request 0.6-core CPUs and 356 MiB of memory. |                                                                        |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Minimal specifications                                                                   | Memory: 256 MiB                                                                                                                                                                                                                                                                                     | None                                                                   |
|                                                                                          |                                                                                                                                                                                                                                                                                                     |                                                                        |
|                                                                                          | CPU: 0.25 cores                                                                                                                                                                                                                                                                                     |                                                                        |
|                                                                                          |                                                                                                                                                                                                                                                                                                     |                                                                        |
|                                                                                          | It is recommended that the ratio of CPU (unit: core) to memory (unit: GiB) be in the range of 1:1 to 1:8. For example, if CPU is 0.5 cores, the memory should range form 512 MiB to 4 GiB.                                                                                                          |                                                                        |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Container engine CLI                                                                     | crictl                                                                                                                                                                                                                                                                                              | -  Docker container: docker                                            |
|                                                                                          |                                                                                                                                                                                                                                                                                                     | -  containerd container: crictl                                        |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| Pod computing resources                                                                  | The request and limit values must be the same for both CPU and memory.                                                                                                                                                                                                                              | The request and limit values can be different for both CPU and memory. |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+
| :ref:`Host Network <cce_10_0402>`                                                        | Not supported                                                                                                                                                                                                                                                                                       | Supported                                                              |
+------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------+