[MacOS Catalina] Error: Couldn't open /dev/disk2

hiakuna · October 18, 2019 at 3:21 PM

Hello guys,

Everything seems works, but when I try to "Write" this error always happens: Error: Couldn't open /dev/disk2
The sd-card adapter is unlock. I have a Macbook Pro (Early 2015) running MacOS Catalina (10.15).
The only weird thing it's that when I chose the folder for th download, or chose the download file, and the LibreELEC needs to interact with Finder/iCloud Drive this Error appears too, but it does not prevent me from selecting the correct folder or file.
I attached the relevant print screens.

Thanks in advance

phkrief · October 19, 2019 at 10:56 PM

I have exactly the same issue. Thx for your help

tbouska · October 20, 2019 at 8:54 AM

This happened to me as well and I suspect it to be related to MacOS Catalina post [LibreELEC Forum]

This is how you flash the image manually on Mac:

Get LibreELEC-xxxxx.img.gz for your device from Direct Downloads
Unpack it: gunzip -d LibreELEC-Generic.x86_64-9.0.2.img.gz (the filename can be different, I will continue to refer to my case going forward)
Determine the disk device corresponding to USB/SD Card you want to flash to:
1. Execute diskutil list
2. Plug the device you'll be flashing the image to
3. Execute diskutil list again and take note of the new disk which appeared (I will refer to /dev/disk2 going forward)
4. Be 200% sure that you took note of the right device so that you don't damage your system. It is very unlikely that your USB flash or SD card is represented as /dev/disk0, because that is almost always the disk on which your system is installed
Unmount the disk: diskutil unmountDisk /dev/disk2 (it was /dev/disk2 in my case, yours can be different, so replace the disk number in all the following commands)
Zero out the partition map: sudo dd if=/dev/zero of=/dev/rdisk2 bs=1024 count=1 (now you are accessing the disk in raw, so the device name is /dev/rdisk2 and not /dev/disk2)
Flash: sudo dd if=LibreELEC-Generic.x86_64-9.0.2.img.gz of=/dev/rdisk2 bs=4m (it will take a while and no progress is printed, be patient and don't unplug the USB/SD Card)
Unmount the disk: diskutil unmountDisk /dev/disk2

Nico · November 5, 2019 at 2:23 PM

Hi thanks for the support. I try to follow your instruction but at instruction 5 the system is asking for a pasword??

I have not set any password?

Can you help?

zdzichu6969 · November 5, 2019 at 2:50 PM

Quote from liemnico@gmail.com

Hi thanks for the support. I try to follow your instruction but at instruction 5 the system is asking for a pasword??

I have not set any password?

Can you help?

Your sudo password shpuld me same with your account.

Nico · November 5, 2019 at 4:31 PM

yes but i have no permission

GermaNico:~ Liem$ sudo dd if=/dev/zero of=/dev/rdisk2 bs=1024 count=1

Password:

dd: /dev/rdisk2: Operation not permitted

GermaNico:~ Liem$

mrlindstrom · November 5, 2019 at 5:52 PM

Quote from liemnico@gmail.com

yes but i have no permission

GermaNico:~ Liem$ sudo dd if=/dev/zero of=/dev/rdisk2 bs=1024 count=1

Password:

dd: /dev/rdisk2: Operation not permitted

GermaNico:~ Liem$

Looks like there were some typos in steps 5 and 6. Change the /dev/rdisk2 to /dev/disk2 in both commands and also change the LibreELEC-Generic.x86_64-9.0.2.img.gz to LibreELEC-Generic.x86_64-9.0.2.img in step 6.

Nico · November 5, 2019 at 9:12 PM

Sorry but my understanding is that Tbouska ment it to change it with the extra "r"

Further the command is accepted but it seems that in catalina it is now not permitting it any more.

This is why libereelec USB-CD creator is not working on a mac and the error: Couldn't open /dev/disk2 is shown.

mrlindstrom · November 6, 2019 at 1:19 AM

Quote from liemnico@gmail.com

Sorry but my understanding is that Tbouska ment it to change it with the extra "r"

Further the command is accepted but it seems that in catalina it is now not permitting it any more.

This is why libereelec USB-CD creator is not working on a mac and the error: Couldn't open /dev/disk2 is shown.

I believe it is some kind of permission issue with the creator program as when it runs it seems to run as root and hence the documents/desktop/icloud folders don't work properly. I just ran through all of the terminal commands on my Macbook with Catalina without issue.

Nico · November 6, 2019 at 7:59 AM

Sorry All,

But it is suddenly working Thanks for the support. Indeed it has something to do with documents/desktop/icloud folders don't work properly.

If I turn icloud off it work!

Nico

**vpeter** · November 6, 2019 at 9:17 AM

I hope everybody understands how dd works and that correct output device is used.

macsvenson · November 17, 2019 at 1:55 PM

Hi,

sorry, but I have also error with USB-SD Creator tool of OS X - Error: Couldn't open /dev/disk2

What can I do???

Fuuga · November 17, 2019 at 5:44 PM

Go to System Preferences -> Security & Privacy

Select Privacy tab

Open the lock (enter your pwd when asked)

From the left side select 'Full disk access'

From the right side press plus button and add LibElec USB-CD Creator into the list on the right.

Quit LibElec USB-CD creator if open

Re-open LibElec USB-CD creator, select downloaded image or download one, etc...

Now writing to the USB/SD should work fine.

macsvenson · November 17, 2019 at 7:35 PM

thanks Fuuga for the instruction. But the Errormessage is same - Error: Couldn't open /dev/disk2

macsvenson · November 19, 2019 at 6:14 PM

Not ideas?

macsvenson · November 20, 2019 at 3:43 PM

I used balenaEtcher to create the SD for my Pi.

alper · November 29, 2019 at 11:22 PM

I also used Etcher but says permission denied. I run the etcher from terminal and worked.

sudo /Applications/http://Etcher.app/Contents/MacOS/Etcher

kendrickb27 · February 13, 2021 at 6:41 PM

Is step 5 necessary? Isn't step 6 overwriting those same bytes? Or am I misunderstanding something?