adding new datasource to an existing RRD

Question

I have few 100s of rrds and i want to add 5 extra datasource to all of those rrds.

1. Is it advisable to do so
2. Whats the best way and the fastest way to do

Answer 1

If you're using PNP4Nagios (https://docs.pnp4nagios.org/pnp-0.6/start), they provide a utility script rrd_modify.pl for modifying existing RRD data files.

    $ rrd_modify.pl -h

   === rrd_modify.pl 0.01 ===
   Copyright (c) 2012 PNP4Nagios Developer Team (http://www.pnp4nagios.org)

   This script can be used to alter the number of data sources of an RRD file.

   Usage:
   rrd_modify.pl RRD_file insert|delete start_ds[,no_of_cols] [type]

   Arguments:
   RRD_file
      the location of the RRD file. It will NOT be overwritten but appended
      by ".chg"
   insert or delete
      the operation to be executed
   start_ds
      the position at which the operation starts (1..no of data sources+1)
   no_of_cols
      (an optional) number of columns which will be added/deleted
   type
      the data type (one of GAUGE, COUNTER)
                Defaults to GAUGE if not specified for insert operations
        (DERIVE, ABSOLUTE, COMPUTE have not been tested and might result in
                 errors during creation of a new RRD file)