NAME

       rrdtune - Modify some basic properties of a Round Robin Database

SYNOPSIS

       rrdtool tune filename [--heartbeat|-h ds-name:heartbeat] [--minimum|-i ds-name:min] [--maximum|-a ds-
       name:max] [--data-source-type|-d ds-name:DST] [--data-source-rename|-r old-name:new-name]
       [--deltapos scale-value] [--deltaneg scale-value] [--failure-threshold failure-threshold]
       [--window-length window-length] [--alpha adaption-parameter] [--beta adaption-parameter]
       [--gamma adaption-parameter] [--gamma-deviation adaption-parameter] [--smoothing-window fraction-of-
       season] [--smoothing-window-deviation fraction-of-season] [--aberrant-reset ds-name]

DESCRIPTION

       The tune option allows you to alter some of the basic configuration values stored in the header area of a
       Round Robin Database (RRD).

       One application of the tune function is to relax the validation rules on an RRD. This allows to fill a
       new RRD with data available in larger intervals than what you would normally want to permit. Be very
       careful with tune operations for COMPUTE data sources.  Setting the min, max, and  heartbeat for a
       COMPUTE data source without changing the data source type to a non-COMPUTE DST WILL corrupt the data
       source header in the RRD.

       A second application of the tune function is to set or alter parameters used by the specialized function
       RRAs for aberrant behavior detection.

       filename
               The name of the RRD you want to tune.

       --heartbeat|-h ds-name:heartbeat
               modify the heartbeat of a data source. By setting this to a high value the RRD will accept things
               like one value per day.

       --minimum|-i ds-name:min
               alter  the  minimum  value  acceptable  as  input  from the data source.  Setting min to 'U' will
               disable this limit.

       --maximum|-a ds-name:max
               alter the maximum value acceptable as input from the  data  source.   Setting  max  to  'U'  will
               disable this limit.

       --data-source-type|-d ds-name:DST
               alter the type DST of a data source.

       --data-source-rename|-r old-name:new-name
               rename a data source.

       --deltapos scale-value
               Alter  the deviation scaling factor for the upper bound of the confidence band used internally to
               calculate violations for the FAILURES RRA. The default value is 2. Note that  this  parameter  is
               not  related to graphing confidence bounds which must be specified as a CDEF argument to generate
               a graph with confidence bounds. The graph scale factor need not to  agree  with  the  value  used
               internally by the FAILURES RRA.

       --deltaneg scale-value
               Alter  the deviation scaling factor for the lower bound of the confidence band used internally to
               calculate violations for the FAILURES RRA. The default value  is  2.  As  with  --deltapos,  this
               argument is unrelated to the scale factor chosen when graphing confidence bounds.

       --failure-threshold failure-threshold
               Alter  the  number  of  confidence bound violations that constitute a failure for purposes of the
               FAILURES RRA. This must be an integer less than or equal to the window  length  of  the  FAILURES
               RRA.  This restriction is not verified by the tune option, so one can reset failure-threshold and
               window-length simultaneously. Setting this option will reset the count of violations to 0.

       --window-length window-length
               Alter the number of time points in the temporal window for determining failures. This must be  an
               integer  greater than or equal to the window length of the FAILURES RRA and less than or equal to
               28. Setting this option will reset the count of violations to 0.

       --alpha adaption-parameter
               Alter the intercept  adaptation  parameter  for  the  Holt-Winters  forecasting  algorithm.  This
               parameter must be between 0 and 1.

       --beta adaption-parameter
               Alter  the  slope adaptation parameter for the Holt-Winters forecasting algorithm. This parameter
               must be between 0 and 1.

       --gamma adaption-parameter
               Alter the seasonal coefficient adaptation parameter for the SEASONAL RRA. This parameter must  be
               between 0 and 1.

       --gamma-deviation adaption-parameter
               Alter the seasonal deviation adaptation parameter for the DEVSEASONAL RRA. This parameter must be
               between 0 and 1.

       --smoothing-window fraction-of-season
               Alter the size of the smoothing window for the SEASONAL RRA. This must be between 0 and 1.

       --smoothing-window-deviation fraction-of-season
               Alter the size of the smoothing window for the DEVSEASONAL RRA. This must be between 0 and 1.

       --aberrant-reset ds-name
               This  option  causes  the  aberrant  behavior detection algorithm to reset for the specified data
               source; that is, forget all it is  has  learnt  so  far.   Specifically,  for  the  HWPREDICT  or
               MHWPREDICT RRA, it sets the intercept and slope coefficients to unknown. For the SEASONAL RRA, it
               sets  all  seasonal  coefficients  to  unknown.  For  the  DEVSEASONAL  RRA, it sets all seasonal
               deviation coefficients to unknown. For the FAILURES RRA, it erases the  violation  history.  Note
               that  reset  does  not  erase  past  predictions (the values of the HWPREDICT or MHWPREDICT RRA),
               predicted deviations (the values of the DEVPREDICT RRA), or failure history (the  values  of  the
               FAILURES RRA).  This option will function even if not all the listed RRAs are present.

               Due  to  the  implementation of this option, there is an indirect impact on other data sources in
               the RRD. A smoothing algorithm is applied to SEASONAL and DEVSEASONAL values on a periodic basis.
               During bootstrap initialization this smoothing is deferred. For efficiency, the implementation of
               smoothing is not data source specific. This means that utilizing reset for one data  source  will
               delay  running the smoothing algorithm for all data sources in the file. This is unlikely to have
               serious consequences, unless the data being collected for the non-reset data sources is unusually
               volatile during the reinitialization period of the reset data source.

               Use of this tuning option is advised when the behavior of the data source time series changes  in
               a drastic and permanent manner.

EXAMPLE 1

       "rrdtool tune data.rrd -h in:100000 -h out:100000 -h through:100000"

       Set  the minimum required heartbeat for data sources 'in', 'out' and 'through' to 10'000 seconds which is
       a little over one day in data.rrd.  This would allow to feed old data from MRTG-2.0  right  into  RRDtool
       without generating *UNKNOWN* entries.

EXAMPLE 2

       "rrdtool tune monitor.rrd --window-length 5 --failure-threshold 3"

       If  the  FAILURES  RRA  is  implicitly  created,  the default window-length is 9 and the default failure-
       threshold is 7. This command now defines a failure as 3 or more violations in a temporal window of 5 time
       points.

AUTHOR

       Tobias Oetiker <tobi@oetiker.ch>

1.4.7                                              2008-03-15                                         RRDTUNE(1)