MAXDATAPAGES 

The database parameter MAXDATAPAGES restricts the overall size (in pages) of all devspaces.

You can only create another devspace when the value for MAXDATAPAGES is greater than the sum of the configured pages of all current devspaces. This new devspace cannot be bigger than the difference between the total disk space configured with MAXDATAPAGES and the sum of all previous devspaces.

The database parameter MAXDATAPAGES is defined when the database instance is installed. Its default reserve is the same size as the largest possible devspace so a devspace of this size can be added if necessary.

If the reserve is filled to capacity once a devspace is added, the Database Manager increases the parameter MAXDATAPAGES by exactly one devspace at the next database instance restart.