Migrating Munin RRD files to a different machine

Have you tried moving your Munin rrd files to a new machine and ended up with this error?

This RRD was created on another architecture

I have a solution and it works recursively.

There are 2 stages to this. Exporting your old rrd files to xml and then converting the xml back into the new rrd format.

Stage 1 - Export the old rrd files into xml

cd into /var/lib/munin and create a file called rrdexport.sh and copy this into it

#!/usr/bin/env bash

foo () {
    for i in $1/*.rrd;do
        rrdtool dump $i /tmp/rrd_dump/$i.xml;
    done
}
# delegate to subprogram
if [ "$1" = "-foo" ]; then
    shift 1
    foo "$@"
    exit $?
fi
find * -type d | xargs mkdir -p /tmp/rrd_dump
find * -type d | xargs -P 2 -I % $SHELL "$0" -foo %

It’s a little rough and ready but it does the job. Lets explain what it does.

find * -type d | xargs mkdir -p /tmp/rrd_dump

First it finds all the directories from where you run it, I am assuming it will be run from ‘var/lib/munin’, then it creates a matching layout in /tmp/rrd_dump

find * -type d | xargs -P 2 -I % $SHELL "$0" -foo %

Secondly it finds all the directories and passes them into the function foo. It uses xargs -P 2 to use to threads at once in an attempt to speed it up a little.

foo () {
    for i in $1/*.rrd;do 
        rrdtool dump $i /tmp/rrd_dump/$i.xml;
    done
}

Function foo accepts a directory name as input. We then find all .rrd files in the directory and using rrdtool export it as xml into /tmp/rrd_dump/directoryname/filename.rrd

Stage 2 - Convert the exported xml into the new rrd format

I have skipped a stage here, the one where you copy the /tmp/rrd_dump directory onto your new machine. I am sure you can do this without my help.

Now we will do the same as before but in reverse. In your rrd_dump directory create a files named rrdrestore.sh

#!/usr/bin/env bash

restore () {
    for i in $1/*.xml;do
        mkdir -p "/var/lib/munin/${i%.rrd.xml}";
        rrdtool restore "$i" "/var/lib/munin/${i%.xml}";
    done
}
# delegate to subprogram
if [ "$1" = "-restore" ]; then
    shift 1
    restore "$@"
    exit $?
fi
#find * -type d | xargs mkdir -p /var/lib/munin/
find * -type d | xargs -P 2 -I % $SHELL "$0" -restore %

You might have to tweak the file permissions once you have finished but all you historical data should now have been transferred onto your new system.