Luks
Installation
sudo apt-get install cryptsetup
sudo yum install cryptsetup-luks
Setup
Creating a Luks encrypted USB disk
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Format the device and set the password
sudo cryptsetup -y -v luksFormat /dev/xvdc
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Open the container
sudo cryptsetup luksOpen /dev/xvdc backup
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Verify the mapper has been assigned and the container opened correctly.
ls -l /dev/mapper/backup
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Put a filesystem on it. First zero the partition and the put the FS on it. This can take hours and depends on the size of the disk used and the system resources (2TB took ~20h for me).
Without Progress bar:
sudo dd if=/dev/zero of=/dev/mapper/backup
With progress bar:
sudo time pv -tpreb /dev/zero | sudo dd of=/dev/mapper/backup bs=128M
Create a FS:
sudo mkfs.ext4 /dev/mapper/backup
Maintenance
Status
View the status of a current mapping
sudo cryptsetup -v status backup
Mount
Mount and access the data at /mnt/disk
sudo cryptsetup luksOpen /dev/xvdc backup
sudo mount /dev/mapper/backup /mnt/disk
Unmount
Unmount the disk and close the container.
sudo umount /mnt/disk
sudo cryptsetup luksClose backup
Change passphrase
New passphrase needs to be provided.
sudo cryptsetup luksDump /dev/xvdc
sudo cryptsetup luksAddKey /dev/xvdc
Remove passphrase
The old passphrase needs to be entered.
sudo cryptsetup luksRemoveKey /dev/xvdc