startupdisk

Startupdisk is a term that can refer to several different concepts related to computer startup processes, primarily within Apple's macOS operating system. One common usage refers to a bootable volume that the system is configured to start from. When a Mac boots, it checks for a designated startup disk to load its operating system. This disk is typically the primary internal hard drive or SSD where macOS is installed. However, users can select other volumes, such as external drives or network volumes, to serve as the startup disk. This is often done to install a new operating system, troubleshoot existing issues, or run a different version of macOS.

The concept of a startup disk is managed within the macOS System Settings or System Preferences. Users can access these settings to choose their preferred startup volume. If a startup disk is not found or is corrupted, the Mac may display an error message, such as a folder with a question mark, indicating it cannot locate a bootable system. In older versions of macOS, the startup disk could be selected by holding down the Option key during boot, which would present a boot manager allowing the user to choose from available startup volumes. The term "startupdisk" itself is not a specific application or utility, but rather a descriptive term for the chosen boot volume.