fixes for better web rendering

[rrdtool-all.git] / program / doc / rrdcreate.pod

diff --git a/program/doc/rrdcreate.pod b/program/doc/rrdcreate.pod
index 3d4b8dd8eadcd982e7a62a3cfa98f211b1d661ae..a47acbbaaf17e95b4c4adc7761343a0d18f19533 100644 (file)
--- a/program/doc/rrdcreate.pod
+++ b/program/doc/rrdcreate.pod
@@ -16,7 +16,7 @@ The create function of RRDtool lets you set up new Round Robin
 Database (B<RRD>) files.  The file is created at its final, full size
 and filled with I<*UNKNOWN*> data.
 
-=over 8
+=over
 
 =item I<filename>
 
@@ -63,7 +63,7 @@ In order to decide which data source type to use, review the
 definitions that follow. Also consult the section on "HOW TO MEASURE"
 for further insight.
 
-=over 4
+=over
 
 =item B<GAUGE>
 
@@ -89,9 +89,7 @@ room. Internally, derive works exactly like COUNTER but without
 overflow checks. So if your counter does not reset at 32 or 64 bit you
 might want to use DERIVE and combine it with a MIN value of 0.
 
-=over
-
-=item NOTE on COUNTER vs DERIVE
+NOTE on COUNTER vs DERIVE
 
 by Don Baarda E<lt>don.baarda@baesystems.comE<gt>
 
@@ -110,8 +108,6 @@ probably preferable. If you are using a 64bit counter, just about any max
 setting will eliminate the possibility of mistaking a reset for a counter
 wrap.
 
-=back
-
 =item B<ABSOLUTE>
 
 is for counters which get reset upon reading. This is used for fast counters
@@ -180,7 +176,9 @@ B<RRA:>I<AVERAGE | MIN | MAX | LAST>B<:>I<xff>B<:>I<steps>B<:>I<rows>
 
 I<xff> The xfiles factor defines what part of a consolidation interval may
 be made up from I<*UNKNOWN*> data while the consolidated value is still
-regarded as known.
+regarded as known. It is given as the ratio of allowed I<*UNKNOWN*> PDPs
+to the number of PDPs in the interval. Thus, it ranges from 0 to 1 (exclusive).
+
 
 I<steps> defines how many of these I<primary data points> are used to build
 a I<consolidated data point> which then goes into the archive.
@@ -200,7 +198,7 @@ flagging aberrant behavior in the data source time series:
 
 =item *
 
-B<RRA:>I<HWPREDICT>B<:>I<rows>B<:>I<alpha>B<:>I<beta>B<:>I<seasonal period>B<:>I<rra-num>
+B<RRA:>I<HWPREDICT>B<:>I<rows>B<:>I<alpha>B<:>I<beta>B<:>I<seasonal period>[B<:>I<rra-num>]
 
 =item *
 
@@ -378,6 +376,44 @@ sample. An extreme example of this might be a "step" of 5 minutes and a
 result in all the PDPs for that entire day period being set to the
 same average rate. I<-- Don Baarda E<lt>don.baarda@baesystems.comE<gt>>
 
+       time|
+       axis|
+ begin__|00|
+        |01|
+       u|02|----* sample1, restart "hb"-timer
+       u|03|   /
+       u|04|  /
+       u|05| /
+       u|06|/     "hbt" expired
+       u|07|
+        |08|----* sample2, restart "hb" 
+        |09|   / 
+        |10|  /
+       u|11|----* sample3, restart "hb"
+       u|12|   /
+       u|13|  /
+ step1_u|14| /
+       u|15|/     "swt" expired
+       u|16|
+        |17|----* sample4, restart "hb", create "pdp" for step1 = 
+        |18|   /  = unknown due to 10 "u" labled secs > "hb"
+        |19|  /
+        |20| /
+        |21|----* sample5, restart "hb"
+        |22|   /
+        |23|  /
+        |24|----* sample6, restart "hb"
+        |25|   /
+        |26|  /
+        |27|----* sample7, restart "hb"
+ step2__|28|   /
+        |22|  /
+        |23|----* sample8, restart "hb", create "pdp" for step1, create "cdp" 
+        |24|   /
+        |25|  /
+
+graphics by I<vladimir.lavrov@desy.de>.
+
 
 =head1 HOW TO MEASURE
 
@@ -510,4 +546,4 @@ RPN expression handles the divide by zero case.
 
 =head1 AUTHOR
 
-Tobias Oetiker E<lt>oetiker@ee.ethz.chE<gt>
+Tobias Oetiker E<lt>tobi@oetiker.chE<gt>