Where Is crypttab on Linux?
crypttab lists encrypted block devices to unlock during boot. The file is /etc/crypttab and each line maps one volume to its source device.
Last updated
The file /etc/crypttab describes encrypted volumes set up at boot. Each non comment line has volume name, encrypted device, key file and options.
Unlocked volumes appear under /dev/mapper. Entries are processed with cryptsetup and systemd cryptsetup units or initramfs hooks, so errors can pause boot for a passphrase prompt.
Where Linux stores this, by platform
/etc/crypttab
Plain text table. Use stable identifiers such as UUID values for the source device. Key file none prompts at boot. Requires root to edit and to read referenced key files.
Frequently asked questions
What is the format of crypttab?
Each line uses volume name, encrypted device, key file and options. Common modes include LUKS and plain dm crypt, plus TrueCrypt and BitLocker support. See man crypttab for field details.
What happens after an unlocked volume is mapped?
The system creates /dev/mapper/volume-name for the decrypted device. Mount it through /etc/fstab or systemd mount units. Swap and tmp options format the mapped device on each boot.
Notice an outdated path? Let us know.