No mountable file systems or something about Mac kernel extensions

By | September 19, 2019

Something happened with Macintosh device, the DMG file which was mounted before without problem cannot be mounted anymore. Several day ago it was OK, I installed several updates, rebooted my Mac couple of times and now something that worked before was rejected. The same result “no mountable file systems” I got when I double clicked on DMG file on Finder windows or when I executed hdiutil command:


# hdiutil mount foo.dmg
hdiutil: mount failed – no mountable file systems

I checked other DMG files downloaded from Internet, for example Skype-8.30.0.50.dmg. The mounting of Skype DMG worked fine. My problematic DMG file was created on Linux machine by genisoimage util and 7zip utility shows that it has ISO type, not HFS type as Skype DMG. The same I could see before when this DMG was mounted successfully with diskutil command:


# diskutil info /dev/disk4
  Device Identifier:        disk4
  Device Node:              /dev/disk4
  Whole:                    Yes
  Part of Whole:            disk4
  Device / Media Name:      Disk Image

  Volume Name:              Foo
  Mounted:                  Yes
  Mount Point:              /Volumes/Foo

  Content (IOContent):      None
  File System Personality:  ISO Rockridge
  Type (Bundle):            cd9660
  Name (User Visible):      ISO 9660 (Rockridge)

  OS Can Be Installed:      No
  Media Type:               Generic
  Protocol:                 Disk Image
  SMART Status:             Not Supported

  Disk Size:                25.3 MB (25337856 Bytes) (exactly 49488 512-Byte-Units)
  Device Block Size:        512 Bytes

  Volume Total Space:       25.3 MB (25337856 Bytes) (exactly 49488 512-Byte-Units)
  Volume Used Space:        25.3 MB (25337856 Bytes) (exactly 49488 512-Byte-Units) (100.0%)
  Volume Available Space:   0 B (0 Bytes) (exactly 0 512-Byte-Units) (0.0%)
  Allocation Block Size:    2048 Bytes

  Read-Only Media:          Yes
  Read-Only Volume:         Yes

  Device Location:          External
  Removable Media:          Removable
  Media Removal:            Software-Activated

  Virtual:                  Yes
  OS 9 Drivers:             No
  Low Level Format:         Not supported

So it looked that the problem with file systems, my Mac did not supported ISO 9660 (CDROM) file system anymore.

The first of all I checked all loading file system kernel extensions and I did not find anything related to ISO 9660:


# kextstat | grep filesystem
   66    1 0xffffff7f81b91000 0x8000     0x8000     com.apple.filesystems.hfs.encodings.kext (1) 7CC455ED-D7F1-3AD4-B362-4A974AFD0991 <7 6 5 4 3 1>
   67    0 0xffffff7f81b99000 0x67000    0x67000    com.apple.filesystems.hfs.kext (407.1.3) F1CDFC19-49BF-35BC-8038-B82DF8C30BDE <66 7 6 5 4 3 1>
  109    0 0xffffff7f81d1f000 0x9000     0x9000     com.apple.filesystems.autofs (3.0) 6B23747D-D072-3862-9DC1-A56D7E0185DB <108 7 6 5 4 3 1>

Then I verified if the kernel extension which supports ISO 9660 (cd9660) existed:


# ls /System/Library/Extensions/ | grep 9660
cd9660.kext

So it was there. I decided to load it manually:


# sudo kextload /System/Library/Extensions/cd9660.kext



Then I checked again the list of file system kernel extensions:


# kextstat | grep filesystem
   66    1 0xffffff7f81b91000 0x8000     0x8000     com.apple.filesystems.hfs.encodings.kext (1) 7CC455ED-D7F1-3AD4-B362-4A974AFD0991 <7 6 5 4 3 1>
   67    0 0xffffff7f81b99000 0x67000    0x67000    com.apple.filesystems.hfs.kext (407.1.3) F1CDFC19-49BF-35BC-8038-B82DF8C30BDE <66 7 6 5 4 3 1>
  109    0 0xffffff7f81d1f000 0x9000     0x9000     com.apple.filesystems.autofs (3.0) 6B23747D-D072-3862-9DC1-A56D7E0185DB <108 7 6 5 4 3 1>
(1.4.4) 11FD858B-5656-30B0-9C57-C94ECB94155D <7 6 5 4 3 1>
MacOSxHghSierra:Downloads root# sudo kextload /System/Library/Extensions/cd9660.kext

Now cd9660.kert was presented. I tried for mount my foo.dmg file agent and it was successful:


# hdiutil mount foo.dmg
/dev/disk4       /Volumes/Foo

Leave a Reply

Your email address will not be published. Required fields are marked *