If it appears that the property or a part of it is so situated that partition cannot be made without great prejudice to the owners, the court may order a sale of the property. Otherwise, upon the requisite proofs being made, the court shall order a partition according to the respective rights of the parties as ascertained by it, may appoint one or more referees to partition the property, and shall designate the portion to remain undivided for the owners whose interests remain unknown or are not ascertained.