The generic mkfs command calls a file system-specific mkfs command, which then creates a file system of a specified type on a specified disk slice. Although the mkfs command can support different types of file systems, in practice you would use it to create UFS, UDFS, or PCFS file systems. To make other types of file systems, you would have to write the software for the file system–specific versions of the mkfs command to use. Normally, you do not run the mkfs command directly. The mkfs command is called by the newfs command.
The generic mkfs command is located in the /usr/sbin directory. For a description of the arguments and options, see mkfs(1M).