GNet Solutions » GNU/Linux Administration

My mail server went down recently, and I managed to have automated rsnapshot backups going to my NAS every weekend. The following method is how I restored the virtual mail server to another virtual instance on a different machine. Luckily I use puppet for managing software packages and configuration, so I had a class for my mail server base configuration. So all I had to do was restore the vmail folder, postfix, and dovecot configurations; then run the ISPConfig update process.

Create New Container¶

• I used the previous container template, mail.tmpl, I just changed the IP address and gateway address to the correct addresses for the new VPS host.
  

  lxc-create -n mail.example.com -t debian-wheezy -f /path/to/mail.tmpl
  

• Once this finished make the container autostart at boot on the VPS host
  

  ln -s /var/lib/lxc/mail.example.com/config /etc/lxc/auto/mail.example.com
  

• Then start or log into the container
  

  lxc-start -n mail.example.com
  

• Then login and change the root password, as well as run a few post installation configurations:
  

  passwd
  dpkg-reconfigure locales
  dpkg-reconfigure tzdata
  

• Update and upgrade
  

  apt-get update
  apt-get upgrade
  

• Join mail server to the puppet domain
  

  puppet agent -vt --waitforcert 30
  

  
  This guide assumes that a proper puppet configuration for the mail server is present.
  • If there is a problem, it is likely that the SSL keys don't match and need to be cleaned from the puppet master server.
    

    puppetca clean mail.example.com
    

• And then on the puppet master server, sign the new puppet client certificate for the mail server.
  

  puppetca sign mail.example.com
  

• This will restore the puppet clients package manifest and configurations. When this finishes, update and upgrade again.
  

  apt-get update
  apt-get upgrade
  

Restoring from backup¶

• I copied the .tar.gz file from the NAS to /root on the mail server.
  

  cd /root
  cp /var/backup/2014-01-25/mail.example.com.tar.gz .
  tar xzf mail.example.com.tar.gz
  cd mail.example.com
  

• Restore the mail server contents
  

  rsync -avh var/vmail /var
  

• Restore the MySQL database
  

  mysql -u root -p < mysqldump/mysqldump_all_databases.sql
  

• Restore local ispconfig folder
  

  rsync -avh usr/local/ispconfig /usr/local/
  

• Restore the server configurations
  

  rsync -avh etc/dovecot /etc/
  rsync -avh etc/postfix /etc/
  rsync -avh etc/mailname /etc/
  rsync -avh etc/getmail /etc/
  

Run ISPConfig update on new virtual server¶

• Now that all the previous server packages and configurations have been restored, run the ISPConfig update to refresh the mail server information with the hosting control panel master node.
  

  /usr/local/ispconfig/server/scripts/update_from_tgz.sh
  

Once the update finished I was able to control the new server from the hosting control panel. The server was successfully migrated.