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Problem

After the RRD migration, for some reason, some graphs are not recording values:

Image Modified

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In the cmc.log, you may see these kinds of messages:

2022-04-06 13:24:41 [4] [client 1] Error accessing RRD: No DS called '12' in '/opt/omd/sites/mysite/var/check_mk/rrd/schiller/Interface_eth1-02.45.rrd'
2022-04-06 13:24:41 [4] [client 1] Error accessing RRD: No DS called '6' in '/opt/omd/sites/mysite/var/check_mk/rrd/schiller/Interface_eth1-02.45.rrd'
2022-04-06 13:24:41 [4] [client 1] Error accessing RRD: No DS called '5' in '/opt/omd/sites/mysite/var/check_mk/rrd/schiller/Interface_eth1-02.45.rrd'
2022-04-06 13:24:41 [4] [client 1] Error accessing RRD: No DS called '11' in '/opt/omd/sites/mysite/var/check_mk/rrd/schiller/Interface_eth1-02.45.rrd'

Solution 1

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1. Change to the RRD directory.

   Code Block
   language bash theme RDark
   OMD[mysite]:~$ cd var/check_mk/rrd/<HOSTNAME>

   
   

2. How many metrics are stored in the .info file?

   Code Block
   language bash theme RDark
   OMD[mysite]:~/var/check_mk/rrd/myhost.txt$ cat Interface_2.info HOST myhost SERVICE Interface eth0 METRICS outqlen;in;out;inerr;inmcast;inbcast;inucast;innucast;indisc;outerr;outmcast;outbcast;outucast;outnucast;outdis

   15 Metrics are stored here
   
   

3. How many datasources do we have in the RRD file?

   Code Block
   language bash theme RDark
   OMD[mysite]:~/var/check_mk/rrd/kirchner_check_mk_agent_output.txt$ rrdtool info Interface_2.rrd |grep "last_ds" ds[1].last_ds = "U" ds[2].last_ds = "U" ds[3].last_ds = "U" ds[4].last_ds = "0" ds[7].last_ds = "U" ds[8].last_ds = "U" ds[9].last_ds = "U" ds[10].last_ds = "U" ds[13].last_ds = "U" ds[14].last_ds = "U" ds[15].last_ds = "U"

   
   

   Note
   11 Datasources are stored. As described in the cmc.log, DS 5,6,11, and 12 are missing.

   
   
   

4. So here we have a mismatch of the number of metrics in the .info (15 Metrics ) file and the amount of Datasources (11 DS) in the .rrd file.
   
   
5. We need to create the missing DS into the RRD file. 
   

   
   

   Warning
   Before continuing here, please note that we do not provide support for any broken .rrd file. Please be careful and do a backup of those files beforehand.

   
   

   1. Stop the site
      

      Code Block
      language bash theme RDark
      OMD[mysite]:~$ omd stop

      
      

   2. Create the four missing datasources

      Code Block
      language bash theme RDark
      OMD[mysite]:~$ rrdtool tune Interface_2.rrd DS:5:GAUGE:8460:0:U OMD[mysite]:~$ rrdtool tune Interface_2.rrd DS:6:GAUGE:8460:0:U OMD[mysite]:~$ rrdtool tune Interface_2.rrd DS:11:GAUGE:8460:0:U OMD[mysite]:~$ rrdtool tune Interface_2.rrd DS:12:GAUGE:8460:0:U

      More information about the command can be found here: https://oss.oetiker.ch/rrdtool/doc/rrdtune.en.html.
      
      

   3. Start the site

      Code Block
      language bash theme RDark
      OMD[mysite]:~$ omd start

      
      

Solution 2

Ensure that the info file does not have less data sources than the rrd file. Thus the rrd file may need to be tuned to contain less data sources, e.g. by

OMD[mysite]:~$ omd stop && rrdtool tune ORA_MYHOST01_SQL_AVQ_MSG_IN_STATUS.rrd DEL:3 && omd start

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