USB Drive Difficulties

SanDisk 128GB Ultra Dual Drive Luxe USB-C Flash Drive

Here is a little interaction that I had with Gemini concerning my USB drive difficulties:

Question:

Is there a free disk utility that I can download that will resurrect my USB memory stick? Apple's disk utility will not reformat it and it is quite new, having been used only a couple of times since purchased a month ago. I used the software tool "balenaetcher" to turn my USB memory stick into an Ubuntu boot disk for a mini-PC that I had been given. As a boot disk it did its job of installing Ubuntu on to the mini-PC but after that I wanted to reformat it so that I could use it to back up files on my Macbook Air. However, it is this reformatting that I've been unable to carry out.

Response:

This is a very common and frustrating problem when using tools like balenaEtcher. The reason this happens is that balenaEtcher doesn't just copy files; it writes an entire image to the USB stick, which includes a different type of partition scheme (like the one used for Linux boot drives). This can make the disk appear to have multiple, small, or unreadable partitions that macOS's Disk Utility has trouble with, especially if it's set to the default "Show only Volumes."

Fortunately, there are several powerful, free methods you can use to "resurrect" your USB stick. Since Disk Utility isn't working for you, here are the most effective alternatives:

1. The Terminal Method (Most Recommended)

This method is the most direct and powerful way to completely wipe the disk and create a new partition map that Disk Utility can understand. It's essentially a more forceful version of what Disk Utility tries to do.

Step-by-step instructions:

1. Open Terminal: You can find it in Applications > Utilities > Terminal or by searching in Spotlight (Command + Space).

2. List your disks: Type the following command and press Enter: diskutil list This will show you a list of all connected drives and their identifiers (e.g., disk0, disk1, disk2).

3. Identify your USB stick: Look for a disk with the correct size. For example, if your USB stick is 32GB, you'll see a line that says something like /dev/disk2 (external, physical) and lists its size. Be absolutely certain you have the right disk number! Wiping the wrong disk could erase your Mac's internal drive.

4. Erase and reformat: Once you've identified your disk (let's assume it's disk2), use the following command. This command will first unmount the disk, then erase it completely, create a new GUID partition map, and format it as exFAT with a new name. diskutil eraseDisk ExFAT "MyUSB" GPT /dev/disk2

   • eraseDisk: The command to erase and format the disk.

   • ExFAT: The file system format you want to use. You can also use FAT32 if you prefer.

   • "MyUSB": The name you want to give the drive. You can change this to anything you like.

   • GPT: The partition scheme. This is a modern, highly compatible standard.

   • /dev/disk2: This is the crucial part. Replace disk2 with the identifier you found in step 3.

5. Press Enter and let the command run. If it's successful, you'll see a series of messages confirming that the disk was unmounted, partitioned, and formatted.

2. GParted (Linux-based Solution)

If you have access to another computer or are comfortable with running a live Linux environment, a tool called GParted is a very reliable way to fix this. It's a graphical partition editor that is often more robust than macOS's built-in tools for dealing with non-standard partition layouts.

1. Create a new bootable Linux USB: Since your current USB stick is non-functional, you'll need another one. Use balenaEtcher again to create a bootable USB with a lightweight Linux distribution like GParted Live or a minimal version of Ubuntu.

2. Boot your mini-PC from this new USB: Start your mini-PC from the GParted Live USB.

3. Run GParted: GParted will automatically launch.

4. Select your faulty USB stick: In the GParted interface, select your original, faulty USB stick from the drop-down menu in the top right corner.

5. Create a new partition table: Go to Device > Create Partition Table. Choose gpt (GUID Partition Table).

6. Create a new partition: Right-click on the "unallocated" space, choose New, and create a new partition with the desired file system (e.g., exfat or fat32).

7. Apply the changes: Click the green checkmark to apply the changes.

8. Re-attempt on your Mac: After this, the USB stick should be fully readable and writable on your MacBook Air.

Why did balenaEtcher cause this?

BalenaEtcher's job is to create a byte-for-byte copy of a bootable image to the USB drive. This process overwrites the entire drive, including its partition table and file system. The Ubuntu image you used has a different partition layout (often with multiple small partitions for things like EFI and the bootloader) that macOS's Disk Utility doesn't always handle gracefully, especially when trying to "erase" it in the typical way. The Terminal and GParted methods are more powerful because they completely destroy the old partition table before trying to create a new one, which is exactly what's needed to fix this issue.

Fortunately, the first method proposed by Gemini (using the terminal) worked and all is well again. I've included the information in this post as a reminder in case I encounter a similar problem in the future.