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I'm experimenting with cryptsetup. My target is to be able to store data into and encrypted file into a non-encrypted hard drive.

I'm doing the following

mkdir /data/test && /data/test

# Create a key
openssl genrsa -out luks_key 4096

# Create file container
dd if=/dev/zero of=device bs=1G count=50 status=progress

# Create and open luks device
cryptsetup -v -y --batch-mode luksFormat device luks_key
sudo cryptsetup -v --batch-mode --key-file=luks_key --type luks open device device_name

# Format the device
sudo mkfs.ext4 -j /dev/mapper/device_name

# Create mount point
mkdir mount_point

# Mount the device
sudo mount -t ext4 /dev/mapper/device_name mount_point

cd mount_point

sudo dd if=/dev/zero of=random_data.bin bs=1G count=1 status=progress

# This will fail until I close the terminal window with "target is busy." error
sudo umount /data/test/mount_point
cryptsetup -v close device_name

All works well up to the point were I try to unmount. The error is:

umount: /data/test/mount_point: target is busy.

The only way to be able to unmount is to close the terminal window. Opening a second one isn't enough. I'm little bit puzzled :)

I run on LinuxMint 18.04 with Linux kernel 5.15.30-25.

Anyone seeing the same thing?

Thanks,

0 Answers0