Unfortunately, if you didn’t already have a Recovery HD partition from a previous Lion installation, and the Mountain Lion installer can’t create the partition, you can’t add it later. So not everyone will get this useful feature. In addition, if your drive has a non-standard partition scheme-for example, if it’s part of a RAID, or if you partitioned the drive using Boot Camp Assistant and then tweaked the drive’s partitions later-the installer won’t be able to create Recovery HD.
For starters, as Apple explains, the drive must be formatted with a GUID partition scheme and Mac OS Extended (Journaled) format, and it must be at least 13GB in size. (If the drive was previously running Lion and already has a Recovery HD partition, the Mountain Lion installer simply updates the partition’s contents.) I say “attempts” because the installer is not always successful. When you install Mountain Lion on a drive, the installer automatically attempts to repartition that drive to create the invisible Recovery HD partition. Why you might not have a Recovery HD partition Separate from-but closely related to-OS X Recovery is a feature called Internet Recovery, which provides similar features even if your Mac’s drive is damaged or has been replaced.