# man > RRDINFO(1)

[_RRDINFO_(1)](https://www.chedong.com/phpMan.php/man/RRDINFO/1/markdown)                                     rrdtool                                    [_RRDINFO_(1)](https://www.chedong.com/phpMan.php/man/RRDINFO/1/markdown)

## NAME
       rrdinfo - extract header information from an RRD

## SYNOPSIS
       **rrdtool info _**filename_ [**--daemon**|**-d _**address_ [**--noflush**|**-F**]]

## DESCRIPTION
       The **info **function prints the header information from an RRD in a parsing friendly format.

       Check rrdcreate if you are uncertain about the meaning of the individual keys.

       _filename_
               The name of the **RRD **you want to examine.

       **--daemon**|**-d _**address_
               Address  of  the  rrdcached  daemon.  If  specified, a "flush" command is sent to the
               server before reading the RRD files. This allows **rrdtool **to return fresh data even if
               the daemon is configured to cache values for a long time.  For  a  list  of  accepted
               formats, see the **-l **option in the rrdcached manual.

                rrdtool info --daemon unix:/var/run/rrdcached.sock /var/lib/rrd/foo.rrd

       **--noflush**|**-F**
               Omit the "flush" command usually sent to the daemon prior to retrieving the data.  If
               all  you  are  interested  in  is  the RRD structure, and not the last update time or
               current values, then this will improve efficiency.

## EXAMPLE
       This is the output generated by running **info **on a simple RRD which contains two data  sources
       and one RRA. Note that the number after the _last_update_ keyword is in seconds since 1970. The
       string  **NaN  **stands  for  _*UNKNOWN*_  data.  In the example it means that this RRD has neither
       minimum nor maximum values defined for either of its data sources.

        filename = "random.rrd"
        rrd_version = "0001"
        step = 300
        last_update = 955892996
        header_size = 2872
        ds[a].type = "GAUGE"
        ds[a].minimal_heartbeat = 600
        ds[a].min = NaN
        ds[a].max = NaN
        ds[a].last_ds = "UNKN"
        ds[a].value = 2.1824421548e+04
        ds[a].unknown_sec = 0
        ds[b].type = "GAUGE"
        ds[b].minimal_heartbeat = 600
        ds[b].min = NaN
        ds[b].max = NaN
        ds[b].last_ds = "UNKN"
        ds[b].value = 3.9620838224e+03
        ds[b].unknown_sec = 0
        rra[0].cf = "AVERAGE"
        rra[0].pdp_per_row = 1
        rra[0].cdp_prep[0].value = nan
        rra[0].cdp_prep[0].unknown_datapoints = 0
        rra[0].cdp_prep[1].value = nan
        rra[0].cdp_prep[1].unknown_datapoints = 0

## ENVIRONMENT VARIABLES
       The following environment variables may be used to change the behavior of "rrdtool info":

       **RRDCACHED_ADDRESS**
           If this environment variable is set it will  have  the  same  effect  as  specifying  the
           "--daemon"  option  on  the  command line. If both are present, the command line argument
           takes precedence.

## AUTHOR
       Tobias Oetiker <<tobi@oetiker.ch>>

1.7.2                                        2024-03-31                                   [_RRDINFO_(1)](https://www.chedong.com/phpMan.php/man/RRDINFO/1/markdown)