cadvisor-gc.service

# It locates on /etc/systemd/system/

[Unit]
Description=Cleaning unnecessary cadvisor system resources. See issue https://github.com/kubernetes/kubernetes/issues/64137.

[Service]
Slice=cadvisor-gc.slice
ExecStart=/opt/cadvisor-gc/cadvisor-gc.sh

[Install]
WantedBy=multi-user.target

cadvisor-gc.sh

#!/bin/bash
# It locates on /opt/cadvisor-gc/

count=0

increaseCount() {
  count=$((count + 1))
}

for i in $(ls /sys/fs/cgroup/systemd/system.slice | grep "^run-r"); do
  pod=$(systemctl list-units --type scope --state running $i | cat | sed -n 's/\(.*\)Kubernetes transient mount for \/var\/lib\/kubelet\/pods\/\(.*\)\/volumes\(.*\)/\2/p')
  if [ ! -f "/var/lib/kubelet/pods/'$pod'" ]; then
    echo -n "Try to stop '$i' systemd scope... "
    systemctl stop $i
    echo "Stopped."
    increaseCount
  fi
done

echo -e "==========\nTotal ${count} systemd scope stopped."

cadvisor-gc.slice

# It locates on /etc/systemd/system/

[Unit]
Description=Limited resources Slice
DefaultDependencies=no
Before=slices.target

[Slice]
CPUQuota=5%
MemoryLimit=0.1G

cadvisor-gc.timer

# It locates on /etc/systemd/system/

[Unit]
Description=Run cadvisor-gc every day

[Timer]
Unit=cadvisor-gc.service
OnCalendar=*-*-* 16:00:00

[Install]
WantedBy=timers.target

Also, I believe the single quotes around $pod break the validation.