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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 (2 recommended) 1 vCPU (2 recommended)
Worker node 0.5 GB (1 recommended) 1 vCPU (2 recommended)
Controller + worker 1 GB (2 recommended) 1 vCPU (2 recommended)

Controller node recommendations for large clusters#

# of Worker nodes # of Pods (besides default) 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).

The specific storage consumption for k0s is as follows:

Role Storage (k0s part)
Controller node ~0.5 GB
Worker node ~1.3 GB
Controller + worker ~1.7 GB

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

Host operating system#

  • Linux (kernel v3.10 or later)
  • Windows Server 2019

Architecture#

  • x86-64
  • ARM64
  • ARMv7

Networking#

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

OS dependencies#

In most cases, k0s does not have any OS level dependencies. The needed kernel configurations are documented here.

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 20.04.3 LTS, OS part of used memory was around 180 MB
  • Hardware: AWS t3.xlarge (4 vCPUs, 16 GB RAM)
  • Pod image: nginx:1.21.4