#先安装epel源[root@vpn ~]# yum install epel-release -y#yum安装vnstat[root@vpn ~]# yum install vnstat -y#创建监控数据库(eth0改成你需要监控的网卡）vnstat -u -i eth0#启动服务并设置开机启动service vnstat startchkconfig vnstat on#查看帮助[root@vpn ~]# vnstat --help vnStat 1.11 by Teemu Toivola <tst at iki dot fi>         -q,  --query          query database         -h,  --hours          show hours         -d,  --days           show days         -m,  --months         show months         -w,  --weeks          show weeks         -t,  --top10          show top10         -s,  --short          use short output         -u,  --update         update database         -i,  --iface          select interface (default: eth0)         -?,  --help           short help         -v,  --version        show version         -tr, --traffic        calculate traffic         -ru, --rateunit       swap configured rate unit         -l,  --live           show transfer rate in real timeSee also "--longhelp" for complete options list and "man vnstat".#流量查看命令[root@vpn ~]# vnstatDatabase updated: Wed Apr  5 22:37:51 2017   eth0 since 04/05/17          rx:  310 KiB      tx:  1.38 MiB      total:  1.68 MiB   monthly                     rx      |     tx      |    total    |   avg. rate     ------------------------+-------------+-------------+---------------       Apr ‘17       310 KiB |    1.38 MiB |    1.68 MiB |    0.03 kbit/s     ------------------------+-------------+-------------+---------------     estimated        --     |      --     |      --     |   daily                     rx      |     tx      |    total    |   avg. rate     ------------------------+-------------+-------------+---------------         today       310 KiB |    1.38 MiB |    1.68 MiB |    0.17 kbit/s     ------------------------+-------------+-------------+---------------     estimated        --     |      --     |      --     |