Encrypted Root

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Revision as of 06:01, December 2, 2020 by Pnoecker (talk | contribs) (load your fstab: i have a strong feeling that with lvm2 installed this build may work. i think its not pulling up crypt_root upon reboot in my last run through because lvm2 was missing.)
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This document describes how to setup a swapless encrypted root partition without lvm.


Rootfs_over_encrypted_lvm works, this page currently does not. you may try to get this working at your own risk!

Prepare the hard drive and partitions

  • List the device to be partitioned, mine is on /dev/sdc
root # lsblk -o name,size,label,partlabel


root # cgdisk /dev/sdc

delete everything.

Command:  new ↵
First sector: 
Last sector: +1M ↵
Hex Code: EF02 ↵
Enter name: BIOS Boot ↵

scroll down to large chunk of free space:

Command: new ↵
First sector: 
Last sector: +128M ↵
Hex Code: EF00 ↵
Enter name: BOOT ↵

scroll down to large chunk of free space:

Command: new ↵
First sector: 
Last sector: 
Hex Code:  8304 ↵
Enter name: FUNTOO ↵
Disk Drive: /dev/sdc
                            Size: 62333952, 29.7 GiB

Part. #     Size        Partition Type            Partition Name
            1007.0 KiB  free space
   1        1024.0 KiB  BIOS boot partition	  BIOS Boot
   2        256.0 MiB   EFI System                BOOT
   3        29.5 GiB    Linux x86-64 root (/)     FUNTOO
Command: write ↵
Command: quit ↵

Encrypt the drive

root # cryptsetup luksFormat --type luks2 --label=FUNTOO /dev/sdc3
  • YES not yes....
  • enter your password:

Initialize the volume

Initialize the volume:

root # cryptsetup luksOpen /dev/sdc3 dmcrypt_root

Create your filesystem

root # mkfs.vfat -F 32 /dev/sdc2
root # fatlabel /dev/sdc2 "BOOT"
root # mkfs.ext4 /dev/mapper/dmcrypt_root


root # mkdir /mnt/funtoo
root # mount /dev/mapper/dmcrypt_root /mnt/funtoo
root # mkdir  /mnt/funtoo/boot
root # mount /dev/sdc2 /mnt/funtoo/boot

Get Funtoo Gnome

You can pull your Subarches gnome tarball if you wish:

root # cd /mnt/funtoo
root # wget https://build.funtoo.org/1.4-release-std/x86-64bit/generic_64/gnome-latest.tar.xz
root # tar --numeric-owner --xattrs --xattrs-include='*' -xpf *gnome* && rm -f *gnome*

Load Funtoo

  • expand your run tmpfs to be half of your ram:
root # mount -t tmpfs tmpfs /run
  • mount up:
root # cd /mnt/funtoo && mount -t proc none proc
mount --rbind /sys sys
mount --rbind /dev dev
mount --rbind /run run
  • chroot in:
root # cd /mnt/funtoo && env -i HOME=/root TERM=$TERM chroot . bash -l
  • Set yo password:
  • set yo hostname:
  • set cloudflare dns resolution for installing:
  • Set yo time zone:
root # passwd
root # echo 'hostname="crypto"' > /etc/conf.d/hostname
root # echo "nameserver" > /etc/resolv.conf
root # ln -sf /usr/share/zoneinfo/America/Detroit /etc/localtime

load your fstab

  • Deploy your fstab:
root # cat > /etc/fstab << "EOF"
LABEL=BOOT /boot vfat noauto,noatime 1 2
/dev/mapper/dmcrypt_root / ext4 noatime,nodiratime,defaults 0 1
tmpfs /run tmpfs rw,nodev,nosuid 0 0
  • load your crypttab:
root # echo "dmcrypt_root LABEL=FUNTOO none luks" >> /etc/crypttab
root # dmsetup table >> /etc/dmtab
  • compile in ram:
root # echo 'PORTAGE_TMPDIR="/run"' > /etc/portage/make.conf
  • Sync & deploy your profile:
root # ego sync && ego profile mix-in encrypted-root
  • Deploy your package.use file:
root # cat > /etc/portage/package.use << "EOF"
*/* lvm device-mapper
sys-kernel/linux-firmware initramfs
root # emerge grub haveged intel-microcode linux-firmware eix cryptsetup lvm2 debian-sources-lts && emerge debian-sources && emerge -vuND @world && emerge --depclean
  • set services:
root # rc-update del swap boot && rc-update add haveged && rc-update add gpm && rc-update add busybox-ntpd
root # rc-update add device-mapper boot
root # rc-update add dmcrypt boot

Bootloader Configuration


boot {
  generate grub
  default "Funtoo Linux"
  timeout 3
"Funtoo Linux" {
	kernel kernel[-v]
	initrd initramfs[-v]
  params += crypt_root=LABEL=FUNTOO dolvm luks=yes real_root=/dev/mapper/dmcrypt_root rootfstype=ext4


  • Install grub in legacy mode:
root # grub-install --target=i386-pc /dev/sdc 
root # ego boot update

EFI from Legacy

  • manually make efi directory:
  • remount /dev/sdc2 to /boot/efi:
  • install efi images:
root # mkdir /boot/efi
root # mount /dev/sdc2 /boot/efi
root # grub-install --target=x86_64-efi /boot/efi

EFI from EFI

root #mount -o remount,rw /sys/firmware/efi/efivars
root #grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id="Funtoo Linux [GRUB]" --recheck /dev/sda
root #ego boot update

Final steps

  • exit chroot, unmount everything,and close encrypted root:
root # exit
root # cd ..
root # umount -lR funtoo
root # cryptsetup luksClose dmcrypt_root


Change your LUKs-encrypted drive's passphrase

You may want to change your encrypted volume’s passphrase or password from time to time. To do so, run the following commands in the console as root:

root # cryptsetup luksChangeKey /dev/sda3

You'll be prompted to enter in the existing passphrase first, then to enter in your new passphrase. You will not be asked to confirm your new passphrase, so be careful when running this operation.

External Resources