1. A computer-readable, non-transitory medium storing a storage control program causing a computer to execute a process comprising: acquiring RAID levels, supportable by a storage device including a plurality of storage mediums, from the storage device; selecting a function type of a storage virtualization function in a host device accessing the storage device on the respective acquired RAID levels in a numerically ascending order of priority allocated to mapping generation rules for the acquired RAID levels, the mapping generation rules being used to map the function types to the respective RAID levels and allocating priority to the function type for each RAID level; determining whether or not a number of RAID levels which have already been mapped to the selected function type is greater than a number of RAID levels which have already been mapped to another function type by equal to or greater than a predetermined number; selecting, when the number of RAID levels which have already been mapped to the selected function type is greater than the number of RAID levels which have already been mapped to another function type by the predetermined number or more, the function type of the next smallest value priority to perform the determining; mapping, when the number of RAID levels which have already been mapped to the selected function type is less than the number of RAID levels which have already been mapped to another function type by the predetermined number, the selected function type to the RAID levels, and incrementing a counter value corresponding to the selected function type; and storing correspondence relationships between the RAID levels and the mapped function types as mapping information.