Terminal command to see the Startup Disk in macOS


If you want to see what the current Startup Disk is on your macOS installation, you can certainly go to System Preferences > Startup Disk.

But if you want to use the terminal instead of the GUI, this command will return the current Startup Disk:

bless –getBoot
If a Startup Disk is set, you’ll see something like this:
/dev/disk0s2
If no Startup Disk is set, you’ll see this error message instead:
Can’t access “efi-boot-device” NVRAM variable
or this one:
Could not interpret boot device as either network or disk
Can’t interpet EFI boot device
And, yes, there’s a typo in the error message (as of macOS 10.12.6, anyway). That should say Can’t interpret instead of Can’t interpet.


One response to “Terminal command to see the Startup Disk in macOS”

  1. Hi this is deprecated on Apple Silicon in Monterey. Bummer!
    ____________________________________
    bless man page macOS 12.5:

    INFO MODE
    Info Mode has the following options:
    –info [directory] Print out the blessed system folder for the volume mounted at
    directory . If directory is not specified, print information
    for the currently selected boot device (which may not
    necessarily be ‘/’ ). This is not supported on Apple Silicon
    based systems.
    –getBoot Print out the logical boot device, based on what is currently
    selected. This option will take into account the fact that the
    firmware may be pointing to an auxiliary booter partition, and
    will print out the corresponding root partition for those
    cases. If the system is configured to NetBoot, a URL matching
    the format of the –server specification for NetBoot mode will
    be printed.
    ____________________________________

    BG-C02FK49GQ05N:~ marcushe$ sudo bless –info
    Can’t statfs , failed with error -1
    Could not extract BSD name from mount point

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