Support for COMPUTE data sources (CDEF data sources). Removes the RPN

[rrdtool.git] / doc / rrdtune.pod

diff --git a/doc/rrdtune.pod b/doc/rrdtune.pod
index f96d8d1..18f478d 100644 (file)
--- a/doc/rrdtune.pod
+++ b/doc/rrdtune.pod
@@ -31,7 +31,10 @@ database as *UNKNOWN*.
 One application of the B<tune> function is to relax the 
 validation rules on an B<RRD>. This allows to fill a new B<RRD> with
 data available in larger intervals than what you would normally want
 One application of the B<tune> function is to relax the 
 validation rules on an B<RRD>. This allows to fill a new B<RRD> with
 data available in larger intervals than what you would normally want

-to permit.
+to permit. Be very careful with tune operations for COMPUTE data sources.
+Setting the I<min>, I<max>, and  I<heartbeat> for a COMPUTE data source
+without changing the data source type to a non-COMPUTE B<DST> WILL corrupt
+the data source header in the B<RRD>.

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


@@ -70,9 +73,9 @@ rename a data source
 Alter the deviation scaling factor for the upper bound of the confidence band
 used internally to calculate violations for the FAILURES B<RRA>. The default
 value is 2. Note that this parameter is not related to graphing confidence
 Alter the deviation scaling factor for the upper bound of the confidence band
 used internally to calculate violations for the FAILURES B<RRA>. The default
 value is 2. Note that this parameter is not related to graphing confidence

-bounds, that scale factor is specified as a CDEV argument to generate a graph with
-confidence bounds. It need agree with the value used internally by the FAILURES
-B<RRA> (although common sense dictates it should).
+bounds, that scale factor must be specified as a CDEF argument to generate 
+a graph with confidence bounds. It need not agree with the value used internally 
+by the FAILURES B<RRA> (although common sense dictates it should).

 
 =item S<B<--deltaneg> I<scale-value>>
 
 
 =item S<B<--deltaneg> I<scale-value>>