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System requirements#

This page describes the system requirements for k0s.

Minimum memory and CPU requirements#

The minimum requirements for k0s detailed below are approximations, and thus your results may vary.

Role Memory (RAM) Virtual CPU (vCPU)
Controller node 1 GB 1 vCPU
Worker node 0.5 GB 1 vCPU
Controller + worker 1 GB 1 vCPU

Controller node recommendations#

# of Worker nodes # of Pods Recommended RAM Recommended vCPU
up to 10 up to 1000 1-2 GB 1-2 vCPU
up to 50 up to 5000 2-4 GB 2-4 vCPU
up to 100 up to 10000 4-8 GB 2-4 vCPU
up to 500 up to 50000 8-16 GB 4-8 vCPU
up to 1000 up to 100000 16-32 GB 8-16 vCPU
up to 5000 up to 150000 32-64 GB 16-32 vCPU

k0s has the standard Kubernetes limits for the maximum number of nodes, pods, etc. For more details, see the Kubernetes considerations for large clusters.

k0s controller node measured memory consumption can be found below on this page.

Storage#

It's recommended to use an SSD for optimal storage performance (cluster latency and throughput are sensitive to storage).

For worker nodes it is required that there is at least 15% relative disk space free.

The specific storage consumption for k0s is as follows:

Role Usage (k0s part) Minimum required
Controller node ~0.5 GB ~0.5 GB
Worker node ~1.3 GB ~1.6 GB
Controller + worker ~1.7 GB ~2.0 GB

Note: The operating system and application requirements must be considered in addition to the k0s part.

Host operating system#

Architecture#

  • x86-64
  • ARM64
  • ARMv7

Networking#

For information on the required ports and protocols, refer to networking.

External runtime dependencies#

k0s strives to be as independent from the OS as possible. The current and past external runtime dependencies are documented here.

To run some automated compatiblility checks on your system, use k0s sysinfo.

Controller node measured memory consumption#

The following table shows the measured memory consumption in the cluster of one controller node.

# of Worker nodes # of Pods (besides default) Memory consumption
1 0 510 MB
1 100 600 MB
20 0 660 MB
20 2000 1000 MB
50 0 790 MB
50 5000 1400 MB
100 0 1000 MB
100 10000 2300 MB
200 0 1500 MB
200 20000 3300 MB

Measurement details:

  • k0s v1.22.4+k0s.2 (default configuration with etcd)
  • Ubuntu Server 20.04.3 LTS, OS part of the used memory was around 180 MB
  • Hardware: AWS t3.xlarge (4 vCPUs, 16 GB RAM)
  • Pod image: nginx:1.21.4