The metadata server is responsible for the formation, migration, maintenance and renewal of blockchain storage contracts. Storage contracts are synchronized with the gateway at first setup and thereafter when a contract has to be replaced or new contracts are required to upload more data. By default storage contracts are valid for 3 months. Storage contracts are grouped together into contract-sets of 20 contracts each. When data is uploaded it is uploaded to one specific contract set at a time. Every gateway includes a total 4x redundant contract-sets.