


 RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))                      1111....0000....44445555                       RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000002222----11112222----22220000



 NNNNAAAAMMMMEEEE
      rrdtool create - Set up a new Round Robin Database

 SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
      rrrrrrrrddddttttoooooooollll ccccrrrreeeeaaaatttteeee _f_i_l_e_n_a_m_e [--------ssssttttaaaarrrrtttt|----bbbb _s_t_a_r_t _t_i_m_e] [--------sssstttteeeepppp|----ssss _s_t_e_p]
      [DDDDSSSS::::_d_s-_n_a_m_e::::_D_S_T::::_h_e_a_r_t_b_e_a_t::::_m_i_n::::_m_a_x] [RRRRRRRRAAAA::::_C_F::::_x_f_f::::_s_t_e_p_s::::_r_o_w_s]

 DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
      The create function of the RRDtool lets you set up new Round Robin
      Database (RRRRRRRRDDDD) files. The file is created at its final, full size and
      filled with *_U_N_K_N_O_W_N* data.

      _f_i_l_e_n_a_m_e
              The name of the RRRRRRRRDDDD you want to create. RRRRRRRRDDDD files should end
              with the extension ._r_r_d. However, rrrrrrrrddddttttoooooooollll will accept any
              filename.

      --------ssssttttaaaarrrrtttt|----bbbb _s_t_a_r_t _t_i_m_e (default: now - 10s)
              Specifies the time in seconds since 1970-01-01 UTC when the
              first value should be added to the RRRRRRRRDDDD. rrrrrrrrddddttttoooooooollll will not
              accept any data timed before or at the time specified.

              See also AT-STYLE TIME SPECIFICATION section in the _r_r_d_f_e_t_c_h
              documentation for more ways to specify time.

      --------sssstttteeeepppp|----ssss _s_t_e_p (default: 300 seconds)
              Specifies the base interval in seconds with which data will be
              fed into the RRRRRRRRDDDD.

      DDDDSSSS::::_d_s-_n_a_m_e::::_D_S_T::::_h_e_a_r_t_b_e_a_t::::_m_i_n::::_m_a_x
              A single RRRRRRRRDDDD can accept input from several data sources (DDDDSSSS).
              (e.g. Incoming and Outgoing traffic on a specific
              communication line). With the DDDDSSSS configuration option you must
              define some basic properties of each data source you want to
              use to feed the RRRRRRRRDDDD.

              _d_s-_n_a_m_e is the name you will use to reference this particular
              data source from an RRRRRRRRDDDD. A _d_s-_n_a_m_e must be 1 to 19 characters
              long in the characters [a-zA-Z0-9_].

              _D_S_T defines the Data Source Type. See the section on "How to
              Measure" below for further insight.  The Datasource Type must
              be one of the following:

              GGGGAAAAUUUUGGGGEEEE
                  is for things like temperatures or number of people in a
                  room or value of a RedHat share.

              CCCCOOOOUUUUNNNNTTTTEEEERRRR
                  is for continuous incrementing counters like the InOctets



                                    - 1 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))                      1111....0000....44445555                       RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000002222----11112222----22220000



                  counter in a router. The CCCCOOOOUUUUNNNNTTTTEEEERRRR data source assumes that
                  the counter never decreases, except when a counter
                  overflows.  The update function takes the overflow into
                  account.  The counter is stored as a per-second rate. When
                  the counter overflows, RRDtool checks if the overflow
                  happened at the 32bit or 64bit border and acts accordingly
                  by adding an appropriate value to the result.

              DDDDEEEERRRRIIIIVVVVEEEE
                  will store the derivative of the line going from the last
                  to the current value of the data source. This can be
                  useful for gauges, for example, to measure the rate of
                  people entering or leaving a 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.

              AAAABBBBSSSSOOOOLLLLUUUUTTTTEEEE
                  is for counters which get reset upon reading. This is used
                  for fast counters which tend to overflow. So instead of
                  reading them normally you reset them after every read to
                  make sure you have a maximal time available before the
                  next overflow. Another usage is for things you count like
                  number of messages since the last update.

              _h_e_a_r_t_b_e_a_t defines the maximum number of seconds that may pass
              between two updates of this data source before the value of
              the data source is assumed to be *_U_N_K_N_O_W_N*.

              _m_i_n and _m_a_x are optional entries defining the expected range
              of the data supplied by this data source. If _m_i_n and/or _m_a_x
              are defined, any value outside the defined range will be
              regarded as *_U_N_K_N_O_W_N*. 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-CCCCOOOOUUUUNNNNTTTTEEEERRRR type DS this would be the max and min data-
              rate expected from the device.

              _I_f _i_n_f_o_r_m_a_t_i_o_n _o_n _m_i_n_i_m_a_l/_m_a_x_i_m_a_l _e_x_p_e_c_t_e_d _v_a_l_u_e_s _i_s
              _a_v_a_i_l_a_b_l_e, _a_l_w_a_y_s _s_e_t _t_h_e _m_i_n _a_n_d/_o_r _m_a_x _p_r_o_p_e_r_t_i_e_s. _T_h_i_s _w_i_l_l
              _h_e_l_p _R_R_D_t_o_o_l _i_n _d_o_i_n_g _a _s_i_m_p_l_e _s_a_n_i_t_y _c_h_e_c_k _o_n _t_h_e _d_a_t_a
              _s_u_p_p_l_i_e_d _w_h_e_n _r_u_n_n_i_n_g _u_p_d_a_t_e.

      RRRRRRRRAAAA::::_C_F::::_x_f_f::::_s_t_e_p_s::::_r_o_w_s
              The purpose of an RRRRRRRRDDDD is to store data in the round robin
              archives (RRRRRRRRAAAA). An archive consists of a number of data values
              from all the defined data-sources (DDDDSSSS) and is defined with an
              RRRRRRRRAAAA line.

              When data is entered into an RRRRRRRRDDDD, it is first fit into time



                                    - 2 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))                      1111....0000....44445555                       RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000002222----11112222----22220000



              slots of the length defined with the ----ssss option becoming a
              _p_r_i_m_a_r_y _d_a_t_a _p_o_i_n_t.

              The data is also consolidated with the consolidation function
              (_C_F) of the archive. The following consolidation functions are
              defined: AAAAVVVVEEEERRRRAAAAGGGGEEEE, MMMMIIIINNNN, MMMMAAAAXXXX, LLLLAAAASSSSTTTT.

              _x_f_f The xfiles factor defines what part of a consolidation
              interval may be made up from *_U_N_K_N_O_W_N* data while the
              consolidated value is still regarded as known.

              _s_t_e_p_s defines how many of these _p_r_i_m_a_r_y _d_a_t_a _p_o_i_n_t_s are used
              to build a _c_o_n_s_o_l_i_d_a_t_e_d _d_a_t_a _p_o_i_n_t which then goes into the
              archive.

              _r_o_w_s defines how many generations of data values are kept in
              an RRRRRRRRAAAA.

 TTTThhhheeee HHHHEEEEAAAARRRRTTTTBBBBEEEEAAAATTTT aaaannnndddd tttthhhheeee SSSSTTTTEEEEPPPP
      Here is an explanation by Don Baarda on the inner workings of rrdtool.
      It may help you to sort out why all this *UNKNOWN* data is popping up
      in your databases:

      RRD gets fed samples at arbitrary times. From these it builds Primary
      Data Points (PDPs) at exact times every "step" interval. The PDPs are
      then accumulated into RRAs.

      The "heartbeat" defines the maximum acceptable interval between
      samples. If the interval between samples is less than "heartbeat",
      then an average rate is calculated and applied for that interval. If
      the interval between samples is longer than "heartbeat", then that
      entire interval is considered "unknown". Note that there are other
      things that can make a sample interval "unknown", such as the rate
      exceeding limits, or even an "unknown" input sample.

      The known rates during a PDP's "step" interval are used to calculate
      an average rate for that PDP. Also, if the total "unknown" time during
      the "step" interval exceeds the "heartbeat", the entire PDP is marked
      as "unknown". This means that a mixture of known and "unknown" sample
      time in a single PDP "step" may or may not add up to enough "unknown"
      time to exceed "heartbeat" and hence mark the whole PDP "unknown". So
      "heartbeat" is not only the maximum acceptable interval between
      samples, but also the maximum acceptable amount of "unknown" time per
      PDP (obviously this is only significant if you have "heartbeat" less
      than "step").

      The "heartbeat" can be short (unusual) or long (typical) relative to
      the "step" interval between PDPs. A short "heartbeat" means you
      require multiple samples per PDP, and if you don't get them mark the
      PDP unknown. A long heartbeat can span multiple "steps", which means



                                    - 3 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))                      1111....0000....44445555                       RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000002222----11112222----22220000



      it is acceptable to have multiple PDPs calculated from a single
      sample. An extreme example of this might be a "step" of 5mins and a
      "heartbeat" of one day, in which case a single sample every day will
      result in all the PDPs for that entire day period being set to the
      same average rate. -- _D_o_n _B_a_a_r_d_a <_d_o_n._b_a_a_r_d_a@_b_a_e_s_y_s_t_e_m_s._c_o_m>

 HHHHOOOOWWWW TTTTOOOO MMMMEEEEAAAASSSSUUUURRRREEEE
      Here are a few hints on how to measure:

      Temperature
          Normally you have some type of meter you can read to get the
          temperature.  The temperature is not realy connected with a time.
          The only connection is that the temperature reading happened at a
          certain time. You can use the GGGGAAAAUUUUGGGGEEEE data source type for this.
          RRRtool will the record your reading together with the time.

      Mail Messages
          Assume you have a method to count the number of messages
          transported by your mailserver in a certain amount of time, this
          give you data like '5 messages in the last 65 seconds'. If you
          look at the count of 5 like and AAAABBBBSSSSOOOOLLLLUUUUTTTTEEEE datatype 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 messages
          per second. If at some later stage you want to know the number of
          messages transported in a day, you can get the average messages
          per second from RRDtool for the day in question and multiply this
          number with the number of seconds in a day. Because all math is
          run with Doubles, the precision should be acceptable.

      It's always a Rate
          RRDtool stores rates in amount/second for COUNTER, DERIVE and
          ABSOLUTE data.  When you plot the data, you will get on the y axis
          amount/second which you might be tempted to convert to absolute
          amount volume by multiplying by the delta-time between the points.
          RRDtool plots continuous data, and as such is not appropriate for
          plotting absolute volumes as for example "total bytes" sent and
          received in a router. What you probably want is plot rates that
          you can scale to for example bytes/hour or plot volumes with
          another tool that draws bar-plots, where the delta-time is clear
          on the plot for each point (such that when you read the graph you
          see for example GB on the y axis, days on the x axis and one bar
          for each day).

 EEEEXXXXAAAAMMMMPPPPLLLLEEEE
      "rrdtool create temperature.rrd --step 300 DS:temp:GAUGE:600:-273:5000
      RRA:AVERAGE:0.5:1:1200 RRA:MIN:0.5:12:2400 RRA:MAX:0.5:12:2400
      RRA:AVERAGE:0.5:12:2400"

      This sets up an RRRRRRRRDDDD called _t_e_m_p_e_r_a_t_u_r_e._r_r_d which accepts one
      temperature value every 300 seconds. If no new data is supplied for



                                    - 4 -        Formatted:  August 20, 2003






 RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))                      1111....0000....44445555                       RRRRRRRRDDDDCCCCRRRREEEEAAAATTTTEEEE((((1111))))
 rrrrrrrrddddttttoooooooollll                                                             rrrrrrrrddddttttoooooooollll
                                 2222000000002222----11112222----22220000



      more than 600 seconds, the temperature becomes *_U_N_K_N_O_W_N*.  The minimum
      acceptable value is -273 and the maximum is 5000.

      A few archives areas are also defined. The first stores the
      temperatures supplied for 100 hours (1200 * 300 seconds = 100 hours).
      The second RRA stores the minimum temperature recorded over every hour
      (12 * 300 seconds = 1 hour), for 100 days (2400 hours). The third and
      the fourth RRA's do the same for the maximum and average temperature,
      respectively.

 AAAAUUUUTTTTHHHHOOOORRRR
      Tobias Oetiker <oetiker@ee.ethz.ch>









































                                    - 5 -        Formatted:  August 20, 2003



