Rootfs over encrypted lvm

This howto describes how to setup LVM, swap, and root with dmcrypt LUKS. It is a standalone installation walk through, based on the official installations finished product. boot is not encrypted.

Prepare the hard drive and partitions

• List the device to be partitioned, mine is on /dev/sdc

root # lsblk -o name,size,label,partlabel

Partition

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 ↵

Encrypting the drive

• luks2 is not backwards compatible, and requires grub 9999 git latest. grub 2.04 does not support luks2 yet. stick with luks1.

root # cryptsetup luksFormat /dev/sdc3

Unlock the volume

Unlock the volume:

root #cryptsetup luksOpen /dev/sdc3 dmcrypt_root

Create logical volumes

root # pvcreate /dev/mapper/dmcrypt_root
root # vgcreate vg /dev/mapper/dmcrypt_root          
root # lvcreate -L2G --name swap vg
root # lvcreate -l 100%FREE --name root vg

Create a filesystem on volumes

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

Mount your partitions

root # swapon /dev/mapper/vg-swap
root # mkdir /mnt/funtoo
root # mount /dev/mapper/vg-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

mount

• mount up:

root # cd /mnt/funtoo && mount -t proc none proc
mount --rbind /sys sys
mount --rbind /dev dev

chroot

• chroot in:

root # env -i HOME=/root TERM=$TERM $(which chroot) /mnt/funtoo 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 1.1.1.1" > /etc/resolv.conf
root # ln -sf /usr/share/zoneinfo/America/Detroit /etc/localtime

fstab

• Deploy your fstab:

root # cat > /etc/fstab << "EOF"
LABEL=BOOT /boot vfat noauto,noatime 1 2
/dev/mapper/vg-swap none swap sw 0 0
/dev/mapper/vg-root / ext4 noatime,nodiratime,defaults 0 1
tmpfs /var/tmp/portage tmpfs uid=portage,gid=portage,mode=775,noatime 0 0
root #tmpfs /var/tmp/portage tmpfs size=2G,uid=portage,gid=portage,mode=775,noatime 0 0
EOF

• Deploy your crypttab:

root # echo "dmcrypt_root PARTLABEL=FUNTOO none luks,discard" >> /etc/crypttab

compile in ram

• compile in ram:

root # mkdir /var/tmp/portage
root # chown portage:portage /var/tmp/portage
root # mount /var/tmp/portage

• Sync:

root # ego sync

• Deploy your ego profile:

root # ego profile mix-in encrypted-root

• Deploy your package.use file:

root # cat > /etc/portage/package.use << "EOF"
*/* device-mapper lvm luks
sys-kernel/linux-firmware initramfs
EOF

• merge stuff:

root # emerge grub haveged intel-microcode linux-firmware eix cryptsetup lvm2 debian-sources debian-sources-lts && emerge -vuND @world && emerge --depclean

• add required services:

root # rc-update add device-mapper sysinit
root # rc-update add dmcrypt sysinit
root # rc-update add haveged && rc-update add gpm && rc-update add busybox-ntpd

• deploy dmtab:

root # dmsetup table >> /etc/dmtab

Bootloader Configuration

• deploy boot.conf

by partlabel it acts buggy, and wont load root possibly to avoid attack surface, by uuid is known to work.

root # cat > /etc/boot.conf << "EOF"
boot {
  generate grub
  default "Funtoo Linux"
  timeout 3
}
"Funtoo Linux" {
	kernel kernel[-v]
	initrd initramfs[-v]
  params += crypt_root=LABEL=FUNTOO dolvm real_root=/dev/mapper/vg-root ro rootfstype=auto resume=swap:/dev/mapper/vg-swap quiet
}
EOF

GRUB

• 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/sdc
root #ego boot update

Final steps

exit chroot, unmount, and close encrypted drive.

root # exit
root # swapoff /dev/dm-1
root # cd ..
root # umount -lR funtoo
root # vgchange -a n
root # cryptsetup luksClose dmcrypt_root

management

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/sdx3

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.

Additional links and information

• crypttab
• Root filesystem over LVM2, DM-Crypt, and RAID
• System Encryption with LUKS for dm-crypt
• arch encrypt entire system
• Wikipedia article on LVM
• Arch Wiki article