How many cloud instances should I reserve on the cloud?

1 or 0. CloudFuzion implements a fully on-demand cluster which requires no fixed assets. For quick start and ease of use, you may choose to have one reserved instance to run the Control Root and the instance management functions, but the compute node instances can be dynamically allocated by CloudFuzion only when there are jobs to run, and they are automatically terminated once the jobs are done. This helps keep your operating cost at a minimum.