grafana面板改爲存到mysql：
# mysql -u root -p'xxxxxx'
> create database grafana;
> grant all on grafana.* to grafana@'localhost' identified by 'xxxxx';
> flush privileges;
# vi /etc/grafana/grafana.ini
[database]
#;type = sqlite3
type = mysql
host = 127.0.0.1:3306
#;name = grafana
name = grafana
#;user = root
user = grafana
#;password =
password = xxxxx
#;path = grafana.db
[session]
#;provider = file
provider = mysql
provider_config = grafana:xxxxxx@tcp(127.0.0.1:3306)/grafana
cookie_name = grafana_sess
cookie_secure = false
session_life_time = 86400
# service grafana-server restart