kubenetesを立ち上げるHW要件は？

サーバにCPUが2つ必要

です。

1つしか積んでいないサーバで起動しようとすると以下エラーになりました。

# kubeadm init --pod-network-cidr=10.10.0.0/16
W0610 14:29:51.947456   21321 configset.go:202] WARNING: kubeadm cannot validate component configs for API groups [kubelet.config.k8s.io kubeproxy.config.k8s.io]
[init] Using Kubernetes version: v1.18.3
[preflight] Running pre-flight checks
        [WARNING IsDockerSystemdCheck]: detected "cgroupfs" as the Docker cgroup driver. The recommended driver is "systemd". Please follow the guide at https://kubernetes.io/docs/setup/cri/
error execution phase preflight: [preflight] Some fatal errors occurred:
        [ERROR NumCPU]: the number of available CPUs 1 is less than the required 2

残念。