OpenNebula sqlite DB (OpenNebula default DB) is called one.db
, and it is placed in /var/lib/one
. Database version mismatch errors arise when an update is performed to OpenNebula and 'oned' is started before the DB is migrated.
The straight solution would be to run onedb upgrade -s /var/lib/one/one.db
and start OpenNebula. The radical solution (that entails losing all the information about hosts, VMs, vnets, etc) would be to erase the DB and start OpenNebula.