macOS USB Mounting Problem

Posting in this forum because people here might also be working cross-platform between OS X and Linux.

I have an external USB drive (USB 2) that was formatted on a CentOS Linux system (ext4 filesystem) and was used as an rsync-based backup for that system. I’m now trying to access this on a Mac (Mavericks) using FUSE for OS X. I’ve done this in the past (‘way past) successfully with other drives, but not this time. When I turn the drive on OS X thinks about it for a while and then pops up a window with “The disk you inserted was not readable by this computer.” Assuming this is an OS X vrs. etc4 issue, I click “Ignore” and look in the Disk Utility. Things look OK there at first glance showing the drive name in the left-side panel with partition information below it, although the latter (disk3s1) is greyed out. It also shows the partition map scheme to be Master Boot Record (which sounds odd to me). The drive is not, however, mounted. Cannot see it anywhere in the GUI (in Finder, for example) and a “df –s” command in the Terminal shows no sign of it. Also, it cannot be ejected/dismounted through the Disk Utility.

Looking in the ever-helpful logs I find an entry in the system log:

kernel[0]: USBMSC Identifier (non-unique): DAA877039488 0x152d 0x2336 0x100, 2

The ID shown (DAA877...) is the same as that shown in the Disk Utility information for the drive. After some googling on this helpful error message I learn little of use.

Taking the drive and putting on a second Linux system there are no problems at all. Put it back on OS X, problems. Replace the USB cable, same problem.

Any ideas as to what’s going on, or how to remedy it? I don’t think it’s even getting to the point where FUSE would kick in.

kryten2 said:

You can try a filesystem check with something like fsck.ext4 on your CentOS Linux system. It's not clear what kind of FUSE you're using but perhaps mounting it manually with some kind of debug option enabled might give you some clues.

Click to expand...

Ran a full set of checks on the Linux system with every tools I could find - no problems with the disk or the filesystem. I'm using OSXFUSE v2.7.5, and I'll have to see if there's some way to use it manually. I don't think that's the problem. I don't see any evidence anywhere that the OS has any handle at all on the disk other than the odd entry in Disk Utility that doesn't allow you to do anything with either the drive or the (greyed-out) partition. The only info I can find in a system log is what I posted earlier, which doesn't give a lot to go on.

Success!

Finally got this to work. I tried installing and reinstalling MACFUSE twice, selecting the option to install fuse-ext2 both times, and both times it failed to install fuse-ext2 with no complaints or explanations. After some googling I found a separate download for fuse-ext2, and after some fighting with OS X's protection against installing impure (as in unblessed/unsigned) apps I was able to get fuse-ext2 installed. After that, and knowing that I needed to do the extra step of mounting the drive in Terminal, all is good. Thanks for the hints and pointers.