When I run
dd inputting from either buffered or raw device of an unmounted volume, which does show up in
diskutil list, I get either "Permission denied" or "Invalid argument".
- MacOS 12.6.1 (Monterey)
- Volumes are not mounted, nor are any snapshots of those volumes mounted.
# diskutil list |grep -E -- '-TM3|ExtData1' 1: APFS Volume ExtData1 282.0 GB disk5s2 1: APFS Volume Mac-TM3 954.4 KB disk7s1 # mount |grep -q -iE 'disks5s2|disk7s1|timemachine' || echo nope nope
- Security & Privacy settings: "Term",
/bin/ddall have "Full Disk" permissions.
- SIP was disabled in recovery mode, and
csrutil statusshows it is disabled.
# csrutil status System Integrity Protection status: disabled.
ddcommand works between
/dev/zero, and the current tty device and to
ddcommand worked to read from the unmounted recovery-hd volume on the main internal drive. -- OH CRAP, HEREIN LIES THE ANSWER
The whole reason I'm doing this is to work-around Mac's horrible redesign of TimeMachine, which effectively makes backup devices unmovable and unclonable.