Wie Du siehst ScreenShot 1 kann man sehr wohl Benutzer ignorieren aktivieren, auch wenn ein OS installiert ist!
Das hat mich auch sehr überrascht, dass du es bisher so verwenden konntest. Es sollte nicht möglich sein.
Hast du schon versucht "diskutil" im Terminal aufzurufen und die disableownership flag zu setzen?
Das geht nur als root, so sei sehr vorsichtig
Im Terminal:
sudo diskutil disableOwnership device
"device" sollte der Pfad zur Festplatte sein.
enableOwnership device
Enable ownership of a volume. The on-root-disk Volume Data-
base at /var/db/volinfo.database is manipulated such that the
User and Group ID settings of files, directories, and links
(file system objects, or "FSOs") on the target volume are
taken into account.
This setting for a particular volume is persistent across
ejects and injects of that volume as seen by the current OS,
even across reboots of that OS, because of the entries in this
OS's Volume Database. Note thus that the setting is not kept
on the target disk, nor is it in-memory.
For some locations of devices (e.g. internal hard disks), con-
sideration of ownership settings on FSOs is the default. For
others (e.g. plug-in USB disks), it is not.
When ownership is disabled, Owner and Group ID settings on
FSOs appear to the user and programs as the current user and
group instead of their actual on-disk settings, in order to
make it easy to use a plug-in disk of which the user has phys-
ical possession.
When ownership is enabled, the Owner and Group ID settings
that exist on the disk are taken into account for determining
access, and exact settings are written to the disk as FSOs are
created. A common reason for having to enable ownership is
when a disk is to contain FSOs whose User and Group ID set-
:
disableOwnership device
Disable ownership of a volume. See enableOwnership above.
Running as root is required.
"device" sollte der Pfad zur Festplatte sein.