In order to backup your undercloud you need to make sure the following items are backed up
The following commands can be used to perform a backup of all data from the undercloud node:
mysqldump --opt --all-databases > /root/undercloud-all-databases.sql tar -czf undercloud-backup-`date +%F`.tar.gz undercloud-all-databases.sql /etc/my.cnf.d/server.cnf /var/lib/glance/images /srv/node /home/stack /etc/pki /opt/stack
The following restore process assumes you are recovering from a failed undercloud node where you have to reinstall it from scratch. It assumes that the hardware layout is the same, and the hostname and undercloud settings of the machine will be the same as well. Once the machine is installed and is in a clean state, re-enable all the subscriptions/repositories needed to install and run TripleO.
Note that unless specified, all commands are run as root.
Then install mariadb server with:
yum install -y mariadb-server
Now restore the MariaDB configuration file and database backup, then start the MariaDB server and load the backup in:
tar -xzC / -f undercloud-backup-$DATE.tar.gz etc/my.cnf.d/server.cnf /root/undercloud-all-databases.sql # Edit /etc/my.cnf.d/server.cnf and comment out 'bind-address' systemctl start mariadb cat /root/undercloud-all-databases.sql | mysql # Now we need to clean out some old permissions to be recreated for i in ceilometer glance heat ironic keystone neutron nova;do mysql -e "drop user $i";done mysql -e 'flush privileges'
Now create the stack user and restore the stack users home directory:
sudo useradd stack sudo passwd stack # specify a password echo "stack ALL=(root) NOPASSWD:ALL" | sudo tee -a /etc/sudoers.d/stack sudo chmod 0440 /etc/sudoers.d/stack
Next restore the stack users home directory:
tar -xzC / -f undercloud-backup-$DATE.tar.gz home/stack
We have to now install the swift and glance base packages, and then restore their data:
yum install -y openstack-glance openstack-swift tar -xzC / -f undercloud-backup-$DATE.tar.gz srv/node var/lib/glance/images # Confirm data is owned by correct user chown -R swift: /srv/node chown -R glance: /var/lib/glance/images
Finally we rerun the undercloud installation from the stack user, making sure to run it in the stack user home dir:
su - stack sudo yum install -y python-tripleoclient # Double check hostname is correctly set in /etc/hosts openstack install undercloud
Having completed the steps above, the undercloud can be expected to automatically restore its connection to the overcloud. The nodes will continue to poll Orchestration (heat) for pending tasks, using a simple HTTP request issued every few seconds.