USB Locked

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Level 1

8 points

USB Locked

I recently tried to erase a USB drive via Disk Utility but when I try to erase it in MS-DOS (FAT) format it gives me the following error:

Unmounting disk

Erasing

Couldn’t open device.

Operation failed…

I go to select the same USB drive on Fetcher but it says it's "locked", which I assume has to do with the Disk Utility not being able to open the device. I've tried erasing it on the terminal and in Safe Mode but nothing works. Any help? The USB Drive I am using is a SanDisk Cruzer Glide 32 GB Flash Drive that is both USB 2.0 and 3.0 compatible.

MacBook Air

Posted on Sep 2, 2017 8:23 PM

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Answer 1

John Galt

Level 10

155,894 points

Sep 2, 2017 9:03 PM in response to Cizox

Most USB flash memory devices have a physical write-protect switch. Toggle it off. You won't be able to erase it until it's unlocked.

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Answer 2

John Galt

Level 10

155,894 points

Sep 3, 2017 9:52 AM in response to Cizox

Since it is formatted FAT32, it's likely the drive became corrupted when disconnecting it. I know that's not what you want to hear, but it's the only likely reason. You might be successful using a Windows PC to reformat it.

Do you have a need it to be formatted for a PC? Journaled (Mac OS Extended) drives cannot be corrupted that way.

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Answer 3

Cizox Author

Level 1

8 points

Sep 3, 2017 8:58 AM in response to John Galt

The only software it comes with is a SanDisk SecureAccess software that protects private files.

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Answer 4

John Galt

Level 10

155,894 points

Sep 3, 2017 8:36 AM in response to Cizox

It's not writable, but it seems you know that already. Since there is no write-protect switch on the drive itself, is there some Sandisk proprietary software installed, preventing its ability to be erased?

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Answer 5

John Galt

Level 10

155,894 points

Sep 3, 2017 10:29 AM in response to Cizox

Cizox wrote:

I just need it formatted for Mac. I have a Windows PC and did try to plug in the USB drive there to see if I could fix it there, but all I saw was the USB drive filled with oddly named files that couldn't be deleted. How would I go on to reformat it using a Windows PC?

I think you would need to ask SanDisk. Mercifully I have repressed all knowledge I ever had about Windows, which wasn't much to begin with.

Don't rule out the possibility the drive simply failed prematurely, or was defective out of the box. SanDisk is a reputable company and ought to replace it without question.

If you decide to replace it with a new one, the very first thing you should do with any storage device (flash drive, SSD, hard disk) is to format it using Disk Utility, thereby preparing it for a Mac and erasing whatever junk their manufacturers are fond of including with them.

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Answer 6

John Galt

Level 10

155,894 points

Sep 2, 2017 10:25 PM in response to Cizox

Does the device appear in the Finder? What does File > Get Info report?

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Answer 7

Cizox Author

Level 1

8 points

Sep 3, 2017 8:05 AM in response to John Galt

The Get Info on the external drive:

Volume type : Physical Device

BSD device node : disk2

Connection : USB

Device tree path : IODeviceTree:/PCI0@0/XHC1@14

Writable : No

Is case-sensitive : No

Volume capacity : 31,406,948,352

Available space (Purgeable + Free) : 0

Purgeable space : 0

Free space : 0

Used space : 31,406,948,352

Owners enabled : No

Is encrypted : No

Can be verified : No

Can be repaired : No

Bootable : No

Journaled : No

Disk number : 2

Media name : SanDisk Cruzer Glide Media

Media type : Generic

Ejectable : Yes

Solid state : No

S.M.A.R.T. status : Not Supported

Here's the Get Info on the USB Flash Drive:

Volume type : Unknown

BSD device node : disk2s1

File system : MS-DOS (FAT32)

Connection : USB

Device tree path : IODeviceTree:/PCI0@0/XHC1@14

Writable : No

Is case-sensitive : No

File system UUID : C99C8B85-ACB5-3804-9DF3-11FBC5C39EE1

Volume capacity : 31,406,931,968

Available space (Purgeable + Free) : 0

Purgeable space : 0

Free space : 0

Used space : 31,406,931,968

Owners enabled : No

Is encrypted : No

Can be verified : Yes

Can be repaired : Yes

Bootable : No

Journaled : No

Disk number : 2

Partition number : 1

Media name :

Media type : Generic

Ejectable : Yes

Solid state : No

Parent disks : disk2

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Answer 8

John Galt

Level 10

155,894 points

Sep 3, 2017 9:37 AM in response to Cizox

... and did you install it?

As a rule such things should never be installed on a Mac. They are generally poorly implemented, cause operational problems, or simply don't work at all. To encrypt storage information on a Mac, use FileVault.

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Answer 9

Cizox Author

Level 1

8 points

Sep 3, 2017 9:44 AM in response to John Galt

I did not install it. All I did when I got the USB drive was plug it in, try to erase everything, then I took out the USB drive without ejecting it, so when I put the USB drive back into the Mac and erase everything on it again, the 'couldn't find device' error showed up.

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Answer 10

Cizox Author

Level 1

8 points

Sep 3, 2017 10:20 AM in response to John Galt

I just need it formatted for Mac. I have a Windows PC and did try to plug in the USB drive there to see if I could fix it there, but all I saw was the USB drive filled with oddly named files that couldn't be deleted. How would I go on to reformat it using a Windows PC?

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