如果docker run redis时，查看日志发现警告：
WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
需要在服务器上执行 sysctl vm.overcommit_memory=1 或者执行一下语句：
echo "vm.overcommit_memory = 1" >> /etc/sysctl.conf \
&& sysctl -p