VNSTATD(1)							   User Manuals 							VNSTATD(1)

NAME

       vnStatd - the alternative for cron based updating

SYNOPSIS

       vnstatd	[  -Ddnpsv?   ]  [  --config file ] [ --daemon ] [ --debug ] [ --help ] [ --noadd ] [ --nodaemon ] [ --pidfile file ] [ --sync ] [
       --version ]

DESCRIPTION

       The purpose of vnstatd is to provide a more flexible way for updating vnstat(1) databases than what using cron for  updating  can  provide.
       The daemon makes possible updating databases more often but at the same time requires less disk access since data can be cached and written
       only later to disk at a user configurable interval. It is also able to track how interfaces come and go	without  the  need  of	additional
       scripts that are required with cron based updates.

       vnstatd	is  the  command for starting the daemon. The daemon can either fork itself to run as a background process or stay attached to the
       terminal.  It supports logging to a user selectable file or using syslog.

       Once started, the daemon will check if there are any databases available in the database directory that has been specified in the  configu-
       ration  file.  New  databases will be created for all available interfaces excluding pseudo interfaces lo, lo0 and sit0 if no databases are
       found during startup.

OPTIONS

       --config file
	      Use file as config file instead of using normal config file search function.

       -d, --daemon
	      Fork process to background and run as a daemon.

       -D, --debug
	      Provide additional output for debug purposes. The process will stay attached to the terminal for output.

       --noadd
	      Disable automatic creation of new databases for all available interfaces if the daemon is started with zero database  found.  Pseudo
	      interfaces lo, lo0 and sit0 are excluded from getting added.

       -n, --nodaemon
	      Stay in foreground attached to the current terminal and start update process.

       -p, --pidfile file
	      Write  the  process  id  to file and use it for locking so that another instance of the daemon cannot be started if the same file is
	      specified.

       -s, --sync
	      Synchronize internal counters in the database with interface counters for all available interfaces before starting traffic  monitor-
	      ing.   Use  this option if the traffic between the previous shutdown and the current startup of the daemon needs to be ignored. This
	      option isn't required in normal use because the daemon will automatically synchronize the internal counters after a  system  reboot,
	      if enought time has passed since the daemon was previously running or if the internal counters are clearly out of sync.

       -v, --version
	      Show current version.

       -?, --help
	      Show a command summary.

CONFIGURATION

       The behaviour of the daemon is configured mainly using the configuration keywords UpdateInterval, PollInterval and SaveInterval in the con-
       figuration file.

       UpdateInterval defines in seconds how often the interface data is updated.  This is similar to the run interval for alternative cron  based
       updating.  However, the difference is that the data doesn't get written to disk during updates.

       PollInterval  defines in seconds how often the list of available interfaces is checked for possible changes. The minimum value is 2 seconds
       and the maximum 60 seconds.  PollInterval also defines the resolution for other intervals.

       SaveInterval defines in minutes how often cached interface data is written to disk.  A write can only occur during the updating	of  inter-
       face data. Therefore, the value should be a multiple of UpdateInterval with a maximum value of 60 minutes.

       The  default values of UpdateInterval 20, SaveInterval 5 and PollInterval 2 are usually suitable for most systems and provide a similar be-
       haviour as cron based updating does but with a better resolution for interface changes and fast interfaces.

       For embedded and/or low power systems more tuned configurations are possible.  In such cases  if  the  interfaces  are  mostly  static  the
       PollInterval can be rised to around 10-30 seconds and UpdateInterval set to 60 seconds. Higher values up to 300 seconds are possible if the
       interface speed is 10 Mbit or less.  SaveInterval can be rised for example to 15, 30 or even 60 minutes depending on  how  often  the  data
       needs to be viewed.

SIGNALS

       The  daemon is listening to signals SIGHUP, SIGINT and SIGTERM.	Sending the SIGHUP signal to the daemon will cause cached data to be writ-
       ten to disk, a rescan of the database directory and a reload of settings from the configuration file. However, the pid  file  will  not	be
       updated even if it's configuration setting has been changed.

       SIGTERM and SIGINT signals will cause the daemon to write all cached data to disk and then exit.

FILES

       /var/lib/vnstat/
	      Default database directory. Files are named according to the monitored interfaces.

       /etc/vnstat.conf
	      Config file that will be used unless $HOME/.vnstatrc exists. See the configuration chapter and vnstat.conf(5) for more information.

       /var/log/vnstat.log
	      Log file that will be used if logging to file is enable and no other file is specified in the config file.

       /var/run/vnstat.pid
	      File used for storing the process id if no other file is specified in the configuration file or using the command line parameter.

RESTRICTIONS

       Updates	needs to be executed at least as often as it is possible for the interface to generate enough traffic to wrap the kernel interface
       traffic counter. Otherwise it is possible that some traffic won't be seen. This isn't an issue for 64 bit kernels but at least  one  update
       every  hour  is	always required in order to provide proper input.  With 32 bit kernels the maximum time between two updates depends on how
       fast the interface can transfer 4 GiB. Calculated theoretical times are:

	      10 Mbit:	      54 minutes
	      100 Mbit:        5 minutes
	      1000 Mbit:      30 seconds

       However, for 1000 Mbit interfaces updating once every minute is usually a working solution.

       Virtual and aliased interfaces cannot be monitored because the kernel doesn't provide traffic information for that type of interfaces. Such
       interfaces are usually named eth0:0, eth0:1, eth0:2 etc. where eth0 is the actual interface being aliased.

AUTHOR

       Teemu Toivola <tst at iki dot fi>

SEE ALSO

       vnstat(1), vnstati(1), vnstat.conf(5), signal(7)

version 1.11							     JUNE 2011								VNSTATD(1)