I can not partition nor use a removable USB disk without file system.
I obtained the following informations:
sh-3.2# diskutil info disk2
Device Identifier: disk2
Device Node: /dev/disk2
Whole: Yes
Part of Whole: disk2
Device / Media Name: IC1100 CF
Volume Name: Not applicable (no file system)
Mounted: Not applicable (no file system)
File System: None
Content (IOContent): None
OS Can Be Installed: No
Media Type: Generic
Protocol: USB
SMART Status: Not Supported
Total Size: 8.0 GB (7994327040 Bytes) (exactly 15613920 512-Byte-Units)
Volume Free Space: Not applicable (no file system)
Device Block Size: 512 Bytes
Read-Only Media: No
Read-Only Volume: Not applicable (no file system)
Device Location: External
Removable Media: Yes
Media Removal: Software-Activated
Virtual: No
OS 9 Drivers: No
Low Level Format: Not supported
After following this guide, I am now able to see the disk in Disk Utility, but it is uninitialized, and when I try to format it, I get the error
Couldn't open device
EDIT: I tried the following:
- Disk Utility > Erase
- Terminal >
diskutil eraseDisk MS-DOS NAME disk2
- Terminal >
diskutil eraseVolume MS-DOS NAME disk2
- Terminal >
diskutil partitionDisk disk2 1 MBR MS-DOS NAME 7.8GB
They ALL lead to the same error: Error: -69877: Couldn't open device
EDIT 2: This is the partition table:
sh-3.2# fdisk -e /dev/disk2
fdisk: could not open MBR file /usr/standalone/i386/boot0: No such file or directory
The signature for this MBR is invalid.
Would you like to initialize the partition table? [y] y
Enter 'help' for information
fdisk:*1> p
Disk: /dev/disk2 geometry: 971/255/63 [15613920 sectors]
Offset: 0 Signature: 0xAA55
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
2: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
3: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
4: 00 0 0 0 - 0 0 0 [ 0 - 0] unused
EDIT 3: If I type fdisk /dev/disk2
, this is shown:
sh-3.2# fdisk /dev/disk2
Disk: /dev/disk2 geometry: 971/255/63 [15613920 sectors]
Signature: 0xD913
Starting Ending
#: id cyl hd sec - cyl hd sec [ start - size]
------------------------------------------------------------------------
1: D5 843 125 41 - 856 48 15 [3289417632 - 1579849264] <Unknown ID>
2: B0 380 233 63 - 580 252 34 [1433382022 - 2359874114] <Unknown ID>
3: 21 542 173 50 - 368 171 22 [ 805962412 - 2236752874] <Unknown ID>
4: C1 311 233 33 - 417 95 7 [3864719105 - 4292535645] DRDOSs FAT12
How can I solve? Thanks
(I'm using Mac OS X 10.11.3)
Best Answer
Restore a DMG (maybe an OSX InstallESD.dmg or any other application) to the disk/drive via Disk Util. This will overwrite it (deleting all data). Then you can partition again how you like.
I have encountered this several times myself with USB pen drives as well as SSDs inside a MacBook Air. Formatting and Erasing brought up the exact same errors you describe. DD didn't work out, Resizing the partition gave me an error about corruption on the disk. First Aid/Scanning & Repairing the volume didn't yield any results, the tool completed with the message that there wasn't anything to repair.
Only the Restoring of a random DMG to the drives made it manageable again.
Hope this helps!