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External HDD: disk cannot open /dev/disk4

L

Lear24driver

macrumors newbie
Original poster
Jun 22, 2020
3
0
I bought an old (2016) LaCie 2TB (Orange) Thunderbolt2 device which had been used as part of a RAID device. I have removed the 2.5" HDD from the enclosure and replaced it with a 1TB SSD. It works fine with an Apple T3toT2 adapter.

I am trying to use the 2.5" HDD on my iMac as an external device but DiskUtility will not let me partition or format the drive, either from the GUI DiskUtility or the Terminal. The GUI DU simply fails the operation with the message "Erasing disk4 and creating 'LaCie2TB' - Unmounting disk - Couldn't modify partition map: (-69874) - Operation failed..." In trying to mount the partition that exists on the disk (disk4s2) I get the following message: "Could not mount "disk4s2". (com.apple.DiskManagement.disenter error -119930868.).

DiskUtility on the desktop indicates "Owners: Disabled" for disk4s2. It seems to be a write protection issue of some kind that is tied to the LaCie enclosure itself. When I return the 2.5" HDD to the original container it partitions and formats perfectly, enables copy and paste of 300MB files but when I remove it and connect it to my iMac everything gets corrupted. I copied 100MB of files to it but when I tried to copy them back to a directory it wouldn't do it and it failed on all tries thereafter.

I have tried connecting the drive to a Linux machine. In the terminal I can partition the drive but trying to format the message returned is: "cannot open /dev/sdb: No such file or directory".

Has anyone had experience with partitioning and re-formatting a drive taken from a LaCie enclosure? Or have any suggestions as to how to address the issues I am having? I am familiar with the Terminal but not an expert by any means and have not been able to discern anything of profit from the references I have seen on the internet with regard to the error messages and codes (-69874) or (-119930868). I am also not knowledgeable about addressing block devices. Any help will be appreciated.

I am running MacOSX 10.15.5 Catalina on a late 2014 (15.1) iMac with 32GB RAM.
 
This is just "a shot from the hip", but...

You might try visiting the LaCie website to see if they have any "utilities" apps for the Mac, used to format and set up their drives.

SOME drives (might be true with yours, or maybe not) from 3rd-party sellers come with "protected partitions" that are created with proprietary software. These partitions might be for security software, etc.

The only way to get rid of them is by using the company's own utility software to remove the partition/software. Once that's done, you can then completely erase it and start over using disk utility.

Again, this is only a guess on my part.
Do you have access to a PC running Windows?
If so, have you tried to erase the drive on that?
 
Thanks. I have contacted both Seagate and LaCie. Seagate says they can do nothing. No proprietary software at their end. Have yet to hear from LaCie.
 
Yes. Thanks for that tip. I downloaded some of it but it won't work on older stuff. Am still waiting for a response from them in hopes of getting a lead. I'm sure it is just a proprietary issue that prohibits normal partitioning and formatting. Many thanks for those who have tried to help.
 
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