My first thought would be to look at the logging configuration on the Edge. This can be done by going to the Edge, the Manage tab, Settings, Configuration, and click the Action button in the Details pane. There is an option to change your logging level, as well as ensuring that Advanced Debugging is disabled. Check the logging level on DNS, and check the logging level on the DHCP, routing, NAT, Load Balancer, and VPN tabs as well. It is typically recommended to configure the edge to use a syslog server for logging. By default, logs should be rotated after 2MB, with a maximum of 5 files retained. In order to gain more space, you can increase the appliance size. To clear space, you can redeploy, although this shouldn't be necessary.
