knowledgebase/linux/networking/monitoring bandwidth usage with vnstat 1 Monitoring bandwidth usage with vnStat vnStat is a very lightweight bandwidth monitoring tool. It's not a packet filter. It works by regularly monitoring /proc entries and updating its simple database of network activity for each interface. Sample output: {code:none} vnstat -m inet (eth0) month rx | tx | total ------------------------+---------------+--------------- Mar '03 15,959 MB | 18,823 MB | 34,782 MB Apr '03 24,645 MB | 20,440 MB | 45,085 MB May '03 31,314 MB | 39,103 MB | 70,417 MB Jun '03 28,116 MB | 42,988 MB | 71,104 MB Jul '03 27,552 MB | 33,924 MB | 61,476 MB Aug '03 37,498 MB | 38,189 MB | 75,687 MB Sep '03 19,750 MB | 17,488 MB | 37,238 MB Oct '03 3,999 MB | 4,492 MB | 8,491 MB ------------------------+---------------+--------------- estimated 18,479 MB | 20,758 MB | 39,237 MB {code} For more 'screenshots' and documentation, refer to the project home page at http://humdi.net/vnstat/ . 1.1 Installation This simple script will help you to install vnstat in your server, no matter which distro you're using {code:none} wget http:\//bliki.rimuhosting.com/space/knowledgebase/linux/networking/monitoring+bandwidth+usage+with+vnstat/installvnstat.sh bash -x installvnstat.sh {code} 1.1 Usage vnStat will record historical bandwidth usage. You can see all options available using --help: {code:none} yves@pressa:~$ vnstat --help vnStat 1.4 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 change interface (default: eth0) -?, --help short help -v, --version show version -tr, --traffic calculate traffic {code} Sample outputs for a low-traffic ppp0 interface: {code:none} vnstat -h eth0 15:45 ^ r | rt | rt | rt r | rt r | rt r r r | rt r r r r r r r r r r r r rt | t t rt r r r r r r r r r r r r rt rt | rt rt rt rt r r r r r r r r r r r r rt rt rt | rt rt rt rt rt rt rt rt rt rt rt r r r r r r r r rt rt rt rt rt -+---------------------------------------------------------------------------> | 16 17 18 19 20 21 22 23 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 h rx (kB) tx (kB) h rx (kB) tx (kB) h rx (kB) tx (kB) 16 2,684 3,135 00 8,960 3,033 08 8,071 1,074 17 4,401 5,433 01 12,740 1,981 09 8,395 1,354 18 2,443 3,056 02 8,955 2,658 10 8,702 1,671 19 2,059 2,563 03 7,748 1,440 11 9,211 3,463 20 3,920 5,227 04 6,386 1,615 12 9,530 5,985 21 3,884 5,491 05 8,187 1,055 13 7,633 8,276 22 2,139 2,289 06 8,100 1,130 14 3,771 4,914 23 18,036 17,629 07 8,101 1,111 15 2,657 2,998 {code} 1 example cron script {code:none} # (Use to post in the top of your crontab) # ----------------- minute (0 - 59) # | -------------- hour (0 - 23) # | | ----------- day of month (1 - 31) # | | | -------- month (1 - 12) # | | | | ----- day of week (0 - 7) (Sunday=0 or 7) # | | | | | # * * * * * command to be executed # check transfer usage for this month every day. if it's greater than 10GB, email me. MAILTO="your-email@email.com" * 1 * * * vnstat --dumpdb | awk --field-separator ";" '{if($1=="m"&&$8=="1"){if($5>10000){print "you have transferred " $5 " MB this month"}}}' {code} 2008-04-15 22:27:13.0 2007-08-23 18:28:40.0 Thu Aug 23 18:29:10 EDT 2007