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,