====== Opening an encrypted partition with a keyfile ======

  * If you suspect that a partition requires a keyfile instead of a passphrase to open check the file:

  cat /etc/crypttab

  * A line like this will indicated such situation:

  shirka_ssd-cache-decrypted UUID=43xxxca6-xxxx-xxxx-xxxx-062a3cc5acee crypt.key luks,discard

  * To open such partition use the following command:

  cryptsetup -d crypt.key luksOpen /dev/bcache0 shirka-bcache0-uncrypt

  * To show existing associated keyslots in the partition:

  sudo cryptsetup luksDump /dev/bcache0