While deleting a LUKS encrypted device using lvremove you would get an error as below :
# lvremove /dev/mapper/datavg-lv_cryptvol Logical volume datavg/lv_cryptvol is used by another device.
The reason being – it is a LUKS encrypted volume. Follow the steps below to delete a LUKS encrypted device.
Deleting LUKS volume
1. Determining the underlying device
Run the following command to determine the underlying device for the LUKS device:
# cryptsetup status cryptvol /dev/mapper/cryptvol is active. type: LUKS1 cipher: aes-cbc-essiv:sha256 keysize: 256 bits device: /dev/mapper/datavg-lv_cryptvol offset: 4096 sectors size: 4190208 sectors mode: read/write
2. Delete existing key on the device
To remove an existing key from LUKS device, use cryptsetup luksRemoveKey command on the device from above command:
# cryptsetup luksRemoveKey /dev/mapper/datavg-lv_cryptvol Enter LUKS passphrase to be deleted: WARNING! ======== This is the last keyslot. Device will become unusable after purging this key. Are you sure? (Type uppercase yes): YES
3. Delete the LUKS device
Once you have deleted the keys from device, you can delete the device using cryptsetup remove command.
# cryptsetup remove /dev/mapper/cryptvol
4. Remove the LVM volume
In this case, the logical volume device can also be removed so that the space is freed for other logical volumes within the volume group to utilize.
# lvremove /dev/mapper/datavg-lv_cryptvol
# blkid /dev/mapper/datavg-lv_cryptvol: UUID="c33892eb-c89e-435e-80cc-e0fb1c64838e" TYPE="crypto_LUKS" /dev/mapper/cryptvol: UUID="0b3cf4e6-14b4-4e93-a24b-98bd3b9e71ce" TYPE="ext4"