The Disk you inserted was not readable by this computer

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The Disk you inserted was not readable by this computer

I have a 15" Macbook Pro with Retina Display. I bought it when it first cam out in the summer. I've been keeping a regular time machine back up of my system ever since. I use a Seagate 3TB GoFlex Desk drive with the Thunderbolt adapter. I haven't had any issues so far and back up's have worked fine.

Yesterday I decided that I wanted to wipe my Mac's internal drive, re-install OS X Mountain Lion, and start fresh. So I forced one more back up on the Seagate, and then proceeded to reformat my mac.

After I reinstalled Mountain Lion and the updates, I plugged in my Seagate/Time Machine Back-Up drive, and got the error, "The disk you inserted was not readable by this computer".

I searched for answers and found some peope suggesting to reset my PRAM and SMC. So I did that, and yet the problem persists. I can see the disk in my Disk Utility, but the options to repair or verify are greyed out.

I did have a seperate back-up drive with my most important documents. However there was some recent work that I had only a time-machine back up of. There must be a solution as I find it unlikely there is something wrong with the drive. Again, the drive was working fine just a day earlier, and now after the reformat, it's unreadable.

Is it possible that the reformat got rid of a driver that gave my mac the ability to read the drive?

Any advice is greatly appreciated.

Sincerely,

- Matt

MacBook Pro (Retina, Mid 2012), Mac OS X (10.7.4)

Posted on Feb 18, 2013 1:41 PM

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Answer 1

Csound1

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Feb 18, 2013 1:53 PM in response to Faidoca

How is the external drive formatted.?

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Answer 2

Faidoca Author

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Feb 18, 2013 2:46 PM in response to Csound1

In Disk Utility I'm able to see that it is formatted in MS-DOS (FAT). I know it should be Mac OS Extended Journaled. I can't remember why I kept it that format. Regardless, time machine worked fine on it in the past, as I was able to back-up and recover files from the disk previously. I can see that there is around 350GB used on disk. I'm assuming that is the time-machine back-up. I just cant seem to access it.

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Answer 3

Csound1

Level 9

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Feb 18, 2013 2:53 PM in response to Faidoca

OSX should be able to read a Fat formatted drive so format is not the problem.

Or maybe not, I just realized that your drive exceeds the max size limit for Fat32 (is it one partition or several), so the format doesn't make sense unless the drive is corrupted.

Can you take a screenshot of the First Aid page in Disk Utility with the partiton (not the drive) selected.

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Answer 4

markwmsn

Level 6

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Feb 18, 2013 3:53 PM in response to Csound1

I didn't think Time Machine would back up to a FAT-formatted drive.

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Answer 5

Csound1

Level 9

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Feb 18, 2013 3:54 PM in response to markwmsn

It won't, which is why I suspect drive (or partition/file table) corruption.

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Answer 6

Feb 18, 2013 3:57 PM in response to markwmsn

Right, it won't back up to a FAT formatted drive. It can't, because Time Machine uses things like hard links that aren't supported in FAT or FAT32. I'm shocked if this worked.

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Answer 7

Feb 18, 2013 4:01 PM in response to Faidoca

Apple's preparation instructions for an external Time Machine disk is that it must be formatted as Mac OS X Extended (Journaled).

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Answer 8

Linc Davis

Level 10

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Feb 18, 2013 4:08 PM in response to Faidoca

The GoFlex drive is a hybrid NAS/USB storage device. I think you were backing up to it over the network, storing the data on a disk image on the underlying FAT volume. Now you're connecting it via USB. Some FAT volumes are known to be unreadable on a Mac.

There are many reports on this site of data-loss disasters involving that device and TIme Machine. I strongly suggest you use something else as your backup disk.

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Answer 9

Csound1

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Feb 18, 2013 4:37 PM in response to William Lloyd

Linc may be right, or the drive is corrupt and Fat is DU interprets the mess (which I have seen) but backing up to NAS is a can of worms.

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Answer 10

markwmsn

Level 6

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Feb 18, 2013 9:49 PM in response to Linc Davis

Linc Davis wrote:

The GoFlex drive is a hybrid NAS/USB storage device. I think you were backing up to it over the network, storing the data on a disk image on the underlying FAT volume. Now you're connecting it via USB. Some FAT volumes are known to be unreadable on a Mac.

There are many reports on this site of data-loss disasters involving that device and TIme Machine. I strongly suggest you use something else as your backup disk.

GoFlex Home is a NAS. The OP is using a GoFlex Desk, which is not. Unless the OP changed adapters in mid stream, the scenario you propose seems unlikely.

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Answer 11

Faidoca Author

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Feb 19, 2013 9:49 AM in response to markwmsn

Thanks everyone for the help! After the last post mentioning the adapter, I took a stab at it and switched the drive over to its original USB adapter and bingo! It worked. I don't really understand why all of a sudden it's unreadable through the Thunderbolt adapter. I'm currently transferring all my stuff from the most recent back-up back onto my Mac. If anyone out there has an answer as to why the Thunderbolt adapter would give me issues like that' I'd love to know.

Again, thanks for the help folks!

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Answer 12

Csound1

Level 9

59,973 points

Feb 19, 2013 11:00 AM in response to Faidoca

Faidoca wrote:

Thanks everyone for the help! After the last post mentioning the adapter, I took a stab at it and switched the drive over to its original USB adapter and bingo! It worked. I don't really understand why all of a sudden it's unreadable through the Thunderbolt adapter. I'm currently transferring all my stuff from the most recent back-up back onto my Mac. If anyone out there has an answer as to why the Thunderbolt adapter would give me issues like that' I'd love to know.

Again, thanks for the help folks!

Thunderbolt adaptor to what? USB or Ethernet?

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Answer 13

markwmsn

Level 6

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Feb 19, 2013 2:26 PM in response to Csound1

Csound1 wrote:

Thunderbolt adaptor to what? USB or Ethernet?

No. The GoFlex line (now mostly called Backup Plus) use a Universal Storage Module (USM) interface between hard drives and adapters to USB3 or Thunderbolt or into their NAS products. The drives can also be plugged directly into USM slots in computers, in theory. USM seems to be a slight variant of SATA.

I wonder, did this GoFlex disk spend some time in a NAS?

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