I’ve had my MacMini for a couple of years, taking it apart and adding an SSD to it, and combining it with the original hard Drive into a Fusion Drive, according to the online instructions. Recently, I had a hot brain and wanted to reinstall the system. As a result, I was dead in the formatting phase and would not move. All kinds of Google Baidu, all kinds of attempts fail.

The first is to separate the Fusion Drive hybrid partitions.

Diskutil CS List # List all Fusion drives

Apple customer support asked me to simply remove the Logical Volume Group, which is the following command.

diskutil cs delete 11111111-2222-3333-4444-555555555555

At the back of the 111… Replace the 555 itself with the UUID of your own Logical Volume Group, which is the bleached first line on the diagram.

Anyway I tested is invalid, so, had to delete step by step. Find the UUID of the logic volume at the bottom of the bleach and execute

diskutil cs deleteVolume 11111111-2222-3333-4444-555555555555

At the back of the 111… Replace 555 with your own UUID. Then execute the command above to remove Logical Volume Group.

In the end, it is still ineffective. Maybe it stays at about 20% of the progress and can’t get down. I probably broke the partition table.

In desperation, try to safely delete the disk

Diskutil disk3 diskutil unmount force /dev/disk3 diskutil disk3 disk3 diskutil unmount force /dev/disk3 disk3 disk3 diskutil unmount force Diskutil unmountDisk /dev/disk3 # diskutil zeroDisk /dev/disk0 # diskutil unmountDisk /dev/disk3 # diskutil zeroDisk /dev/disk0 # diskutil zeroDisk /dev/disk0 #  ~ Started erase on disk2 ~ Error: -69759: Securely erasing data to prevent recovery failed Underlying ~ error: 5: Diskutil eraseDisk HFS+ NAME /dev/disk3 diskutil eraseDisk HFS+ NAME /dev/disk3

Not testing a command here:

fdisk -a hfs /dev/disk3

Diskutil is actually an older version of fdisk. It’s just been used by Apple, it’s been expanded. But fdisk allows a more flexible operation. It doesn’t have to be limited by some of Apple’s security mechanisms. I just didn’t test the command because I was in a more geodesic erasure mode.

Great killer, Unix-like system disk deep format method

Apple is a Unix-like system, so its underlying disk management mode is similar to that of other Unix systems. For example, there are special device drivers such as dev/null or dev/random. The former accepts any input and acts like a real-time garbage dump. The latter, if accessible, outputs a bunch of random data in real time. This can be accessed via cat /dev/random, which needs to be aborted by Ctrl+ C.

Here we use dev/random to solve our disk problem.

When our disk drive fails or has a low grid problem, we can force overwrite the disk with dev/random, which will destroy the partition table and the current format, leaving the drive as a blank disk.

Diskutil list ##### Be careful not to find the wrong disk. The following operations are not recoverable. I want to use disk3 in a lower space. The command is #### cat /dev/random > /dev/disk3

Run for about a minute, then press Ctrl + C to interrupt it. Then perform

diskutil list

If it shows the following, the disk has become empty.

Then, you can partition, format, and reinstall the system in Disk Tools.

Super large killer, withddCommand is low,

Under Linux, the low space utility is dd

dd if=/dev/zero of=/dev/disk2 conv=noerror bs=128k

  • BS = Bytes: Set the size of read-write block to Bytes at the same time, which can replace IBS and OBS

  • Conv = noError: Processing is not stopped when an error occurs.

DiskUtil List: DiskUtil List: DiskUtil List: DiskUtil List

Low grid on the use of 0/1 to cover the entire hard disk, a few hours, depending on the size of the hard disk.

Okay, let it go. I’m going to sleep. ^_^

Oh, and the dragon slayerddrescue

I haven’t tested it yet, but it has been installed with BREW. You can install it first by executing the following command

brew install ddrescue

Basic operation:

Usage: ddrescue [options] infile outfile [mapfile]

For details, please run the command ddrescue –help.