This becomes apparent when you encounter startup problems with your Mac's drive, only to discover that the Recovery HD also isn't working because it's part of the same startup drive.
Nke a ga-abụ ihe nhụjuanya mgbe ị na-enweta nsogbu mmalite na ụgbọala Mac, naanị ịchọpụta na Iweghachite HD adịghị arụ ọrụ, ebe ọ bụ na otu akụkụ ahụ na-amalite.