Munin stores its historical data in RRD (Round Robin Database) files located in /var/lib/munin/ by default. These binary files contain all the metrics collected over time. The directory structure typically follows:
/var/lib/munin/ ├── domain1.example.com │ ├── cpu-user.rrd │ ├── memory-used.rrd │ └── ... ├── domain2.example.com │ ├── disk-usage.rrd │ └── ... └── ...
Before moving anything, ensure both old and new servers run the same Munin version to avoid compatibility issues:
# Check Munin version munin-node -V
Create a complete backup of your existing data:
# Create backup sudo tar -czvf munin_backup.tar.gz /var/lib/munin /etc/munin/munin.conf
Choose one of these reliable transfer methods:
Method 1: Direct Rsync
# On new server sudo rsync -avz -e ssh oldserver:/var/lib/munin/ /var/lib/munin/
Method 2: Tarball Transfer
# On old server sudo tar -czvf munin_data.tar.gz -C /var/lib/munin . # On new server sudo mkdir -p /var/lib/munin sudo tar -xzvf munin_data.tar.gz -C /var/lib/munin
Transfer your configuration files while maintaining proper permissions:
# Copy main config sudo scp oldserver:/etc/munin/munin.conf /etc/munin/ # Copy plugin configs if any sudo scp oldserver:/etc/munin/plugin-conf.d/* /etc/munin/plugin-conf.d/
After transferring files, perform these essential tasks:
# Set proper ownership sudo chown -R munin:munin /var/lib/munin # Restart services sudo systemctl restart munin-node sudo systemctl restart munin-httpd
Use these commands to verify your data transferred correctly:
# Check file count comparison find /var/lib/munin -type f | wc -l # Sample a specific RRD file rrdtool info /var/lib/munin/example.com/cpu-user.rrd
For nodes that will continue reporting to the new server, update their configuration:
# In /etc/munin/munin-node.conf on each node allow ^127\.0\.0\.1$ allow ^192\.168\.1\.100$ # New server IP
For a seamless transition, consider running both servers temporarily while switching DNS or load balancer configurations.
If graphs appear broken after migration:
# Rebuild HTML files sudo su - munin --shell /bin/bash -c /usr/share/munin/munin-update # Check for permission issues sudo munin-check
Before migrating your Munin server, it's crucial to understand where and how data is stored. Munin typically stores its data in:
/var/lib/munin/ # Main data directory ├── munin-update # Update status files ├── munin-data # RRD database files ├── cgi-tmp # CGI generated images └── html # Static HTML output
The most critical components are the RRD (Round Robin Database) files in munin-data which contain all your historical metrics.
First, ensure both servers run the same Munin version to avoid compatibility issues:
# On both old and new servers: munin-node --version
Create a backup of your current configuration:
# On old server: tar -czvf munin_backup.tar.gz /etc/munin /var/lib/munin
Method 1: Direct File Transfer
The simplest approach is to copy the entire data directory:
# On new server: rsync -avz old-server:/var/lib/munin/ /var/lib/munin/
For configuration files:
rsync -avz old-server:/etc/munin/ /etc/munin/
Method 2: Database-Level Migration
If using MySQL backend (less common), dump and restore the database:
# On old server: mysqldump -u munin -p munin_db > munin_db.sql # On new server: mysql -u munin -p munin_db < munin_db.sql
After transferring files, adjust file permissions:
chown -R munin:munin /var/lib/munin chown -R munin:munin /etc/munin
Update the munin-node configuration if IP addresses changed:
# In /etc/munin/munin.conf on new server:
[old-node.example.com]
address 192.168.1.100
use_node_name yes
Check if the RRD files were properly transferred:
rrdtool info /var/lib/munin/munin-data/server1/cpu-user.rrd
Force an immediate update to test functionality:
su - munin --shell=/bin/bash -c "/usr/share/munin/munin-update"
Permission problems: The munin user must have proper access to all files.
# Typical solution: chmod -R 755 /var/lib/munin
Time zone mismatches: Ensure both servers use the same time zone to prevent graph anomalies.
timedatectl list-timezones sudo timedatectl set-timezone Region/City
Consider setting up a cron job for regular Munin data backups:
0 3 * * * root tar -czf /backups/munin-$(date +\%Y\%m\%d).tar.gz /var/lib/munin /etc/munin