Splits
Owners split one server's resources into several servers, for example a proxy and its lobbies.
A server can be split into smaller servers that share its resources. The parent keeps what is left.
Allow splits
Set Split slots on the admin server form under Package & Splits, or let the preset decide. 0 means no splits.
Split a server
The owner opens Split on their server, picks how much memory, disk and CPU the new server gets, and which egg it runs. The new server appears in their list. Subusers of the parent can be copied to it.
Deleting a split gives its resources back to the parent. Admins can add and delete splits on the admin server page without the slot limit.
Suggestions
Splits fit networks well: one parent for the proxy, splits for lobby, survival and minigames, all within the package the customer paid for.