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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 in GB) Virtual CPUs (vCPU)
Controller node 1 1
Worker node 0.5 1
Controller + worker 1 1

Controller node recommendations#

# of worker nodes # of pods Recommended RAM (in GB) Recommended vCPU
10 1000 1-2 1-2
50 5000 2-4 2-4
100 10000 4-8 2-4
500 50000 8-16 4-8
1000 100000 16-32 8-16
5000 150000 32-64 16-32

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
  • aarch64
  • armv7l

Networking#

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

External runtime dependencies#

k0s strives to be as independent from the operating system as possible. See the dedicated section on external runtime dependencies for details on current and past requirements.

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 (in MB)
1 0 510
1 100 600
20 0 660
20 2000 1000
50 0 790
50 5000 1400
100 0 1000
100 10000 2300
200 0 1500
200 20000 3300

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