我们在所有或 rhel 7.5 机器上安装了 docker 服务（5 台机器）
由于一些不清楚的原因，我们看到所有机器上的 docker 服务都停止了（机器在过去 1 年都已启动）
这很奇怪，因为 docker 服务配置了 Restart=always ，所以如果 docker 服务关闭，那么几秒钟后它会自动启动，根据以下 docker 服务配置
TimeoutSec=0
RestartSec=2
Restart=always
和完整的描述：
more /etc/systemd/system/multi-user.target.wants/docker.service
[Unit]
Description=Docker Application Container Engine
Documentation=https://docs.docker.com
BindsTo=containerd.service
After=network-online.target firewalld.service containerd.service
Wants=network-online.target
Requires=docker.socket
[Service]
Type=notify
# the default is not to use systemd for cgroups because the delegate issues still
# exists and systemd currently does not support the cgroup feature set required
# for containers run by docker
ExecStart=/usr/bin/dockerd -H fd:// --containerd=/run/containerd/containerd.sock
ExecReload=/bin/kill -s HUP $MAINPID
TimeoutSec=0
RestartSec=2
Restart=always
# Note that StartLimit* options were moved from "Service" to "Unit" in systemd 229.
# Both the old, and new location are accepted by systemd 229 and up, so using the old location
# to make them work for either version of systemd.
StartLimitBurst=3
# Note that StartLimitInterval was renamed to StartLimitIntervalSec in systemd 230.
# Both the old, and new name are accepted by systemd 230 and up, so using the old name to make
# this option work for either version of systemd.
StartLimitInterval=60s
# Having non-zero Limit*s causes performance problems due to accounting overhead
# in the kernel. We recommend using cgroups to do container-local accounting.
LimitNOFILE=infinity
LimitNPROC=infinity
LimitCORE=infinity
我担心的是 docker 服务 PID 上的某些kill操作kill -9，也许是这种情况，但另一方面，没有用户登录到机器，所以这很奇怪，
有关于此的任何提示吗？