index 86817bd4dbeb60bc0c9233244744cd41e7e20165..38585422c258f0baa3cd2d701b1a06748dda0073 100644 (file)
B<rrdtool> B<create> I<filename>
S<[B<--start>|B<-b> I<start time>]>
S<[B<--step>|B<-s> I<step>]>
+S<[B<--no-overwrite>]>
+S<[B<--daemon> I<address>]>
S<[B<DS:>I<ds-name>B<:>I<DST>B<:>I<dst arguments>]>
S<[B<RRA:>I<CF>B<:>I<cf arguments>]>
Database (B<RRD>) files. The file is created at its final, full size
and filled with I<*UNKNOWN*> data.
-=over 8
-
-=item I<filename>
+=head2 I<filename>
The name of the B<RRD> you want to create. B<RRD> files should end
with the extension F<.rrd>. However, B<RRDtool> will accept any
filename.
-=item B<--start>|B<-b> I<start time> (default: now - 10s)
+=head2 B<--start>|B<-b> I<start time> (default: now - 10s)
Specifies the time in seconds since 1970-01-01 UTC when the first
value should be added to the B<RRD>. B<RRDtool> will not accept
See also AT-STYLE TIME SPECIFICATION section in the
I<rrdfetch> documentation for other ways to specify time.
-=item B<--step>|B<-s> I<step> (default: 300 seconds)
+=head2 B<--step>|B<-s> I<step> (default: 300 seconds)
Specifies the base interval in seconds with which data will be fed
into the B<RRD>.
-=item B<DS:>I<ds-name>B<:>I<DST>B<:>I<dst arguments>
+=head2 B<--no-overwrite>
+
+Do not clobber an existing file of the same name.
+
+=item B<--daemon> I<address>
+
+Address of the L<rrdcached> daemon. For a list of accepted formats, see
+the B<-l> option in the L<rrdcached> manual.
+
+ rrdtool create --daemon unix:/var/run/rrdcached.sock /var/lib/rrd/foo.rrd I<other options>
+
+=head2 B<DS:>I<ds-name>B<:>I<DST>B<:>I<dst arguments>
A single B<RRD> can accept input from several data sources (B<DS>),
for example incoming and outgoing traffic on a specific communication
definitions that follow. Also consult the section on "HOW TO MEASURE"
for further insight.
-=over 4
+=over
=item B<GAUGE>
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
+B<NOTE on COUNTER vs DERIVE>
by Don Baarda E<lt>don.baarda@baesystems.comE<gt>
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
data source is assumed to be I<*UNKNOWN*>.
I<min> and I<max> define the expected range values for data supplied by a
-data source. If I<min> and/or I<max> any value outside the defined range
+data source. If I<min> and/or I<max> are specified any value outside the defined range
will be regarded as I<*UNKNOWN*>. If you do not know or care about min and
max, set them to U for unknown. Note that min and max always refer to the
processed values of the DS. For a traffic-B<COUNTER> type DS this would be
similar to the restriction that B<CDEF>s must refer only to B<DEF>s
and B<CDEF>s previously defined in the same graph command.
-=item B<RRA:>I<CF>B<:>I<cf arguments>
-
+=head2 B<RRA:>I<CF>B<:>I<cf arguments>
The purpose of an B<RRD> is to store data in the round robin archives
(B<RRA>). An archive consists of a number of data values or statistics for
a I<consolidated data point> which then goes into the archive.
I<rows> defines how many generations of data values are kept in an B<RRA>.
-
-=back
+Obviously, this has to be greater than zero.
=head1 Aberrant Behavior Detection with Holt-Winters Forecasting
more than B<half> the "step", the entire PDP is marked
as "unknown". This means that a mixture of known and "unknown" sample
times in a single PDP "step" may or may not add up to enough "known"
-time to warrent for a known PDP.
+time to warrant a known PDP.
The "heartbeat" can be short (unusual) or long (typical) relative to
the "step" interval between PDPs. A short "heartbeat" means you
=item Mail Messages
Assume you have a method to count the number of messages transported by
-your mailserver in a certain amount of time, giving you data like '5
+your mail server in a certain amount of time, giving you data like '5
messages in the last 65 seconds'. If you look at the count of 5 like an
B<ABSOLUTE> data type you can simply update the RRD with the number 5 and the
end time of your monitoring period. RRDtool will then record the number of