为什么即使在禁用交换后 kubeadm 也无法启动？

Question

我正在尝试在装有Ubuntu 16.04 的笔记本电脑中使用 kubeadm 安装 kubernetes 。我禁用了交换，因为 kubelet 在交换时不起作用。我使用的命令是：

swapoff -a

我还注释掉了对 swap in 的引用/etc/fstab。

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>    <dump>  <pass>
# / was on /dev/sda1 during installation
UUID=1d343a19-bd75-47a6-899d-7c8bc93e28ff /            ext4 errors=remount-ro 0    1
# swap was on /dev/sda5 during installation
#UUID=d0200036-b211-4e6e-a194-ac2e51dfb27d none         swap sw           0    0

我通过运行以下命令确认交换已关闭：

free -m
              total        used        free      shared  buff/cache   available
Mem:          15936        2108        9433         954        4394       12465
Swap:             0           0           0

当我启动 kubeadm 时，出现以下错误：

kubeadm init --pod-network-cidr=10.244.0.0/16
[init] Using Kubernetes version: v1.14.2
[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 Swap]: running with swap on is not supported. Please disable swap
[preflight] If you know what you are doing, you can make a check non-fatal with `--ignore-preflight-errors=...`

我也尝试重新启动我的笔记本电脑，但我遇到了同样的错误。原因可能是什么？

Answer 1

下面是根本原因。

检测到“cgroupfs”作为 Docker cgroup 驱动程序。推荐的驱动程序是“systemd”。

您需要更新 docker cgroup 驱动程序。

按照以下修复

cat > /etc/docker/daemon.json <<EOF
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2",
  "storage-opts": [
    "overlay2.override_kernel_check=true"
  ]
}
EOF

mkdir -p /etc/systemd/system/docker.service.d

# Restart Docker
systemctl daemon-reload
systemctl restart docker