Re: dd if=/dev/rdisk12 of=/dev/zero (OT, since macOS)

As already said, I do want to read the device. My problem is the "Invalid argument"

--
Christoph



> Am 01.11.2025 um 15:33 schrieb paul beard <paulbeard@gmail.com>:
> 
> not sure what you are trying to do here but at first glance it looks like if and of are reversed, if you are trying to write /dev/zero to the device. is /dev/rdisk12 what diskutil list returns? 
> 
> On Sat, Nov 1, 2025 at 7:11 AM Christoph Kukulies <kuku@kukulies.org <mailto:kuku@kukulies.org>> wrote:
>> Hi co-readers,
>> 
>> excuse me for coming up with a non FreeBSD question but I'm sure many "also macOS" users are here.
>> I got an SSD external drive today from China. It's supposed to have 10TB and has the name "SEAGATE" engraved on the cover which I haven't opened
>> yet, also because it's clipped together - no screws.
>> 
>> Anyway, I tried
>> 
>> 
>> # dd if=/dev/rdisk12 of=/dev/zero
>> 
>> on it (in a macOS terminal window.
>> 
>> I'm getting 
>> 
>> $ sudo dd if=/dev/rdisk12 of=/dev/zero bs=512
>> Password:
>> dd: /dev/rdisk12: Invalid argument
>> 0+0 records in
>> 0+0 records out
>> 0 bytes transferred in 0.000036 secs (0 bytes/sec)
>> $ 
>> 
>> also without the bs=512 not any better.
>> 
>> An ideas what might be wrong?
>> 
>> --
>> Christoph
>> 
> 
> 
> 
> --
> Paul Beard / www.paulbeard.org/ <http://www.paulbeard.org/>