User:Pnoecker/full disk encryption

This howto describes how to setup LVM, boot, swap, and root with dmcrypt LUKS 1 with grub unlocking the encrypted drive. It is a standalone installation walk through, loosely based on the official installations finished product.

   Warning

You may try this installation method at your own risk! Please note: this guide is outside of the official installation documentation, and cannot be supported. If you choose to use this, we assume you know what you are doing and you are on your own!

Prepare the hard drive and partitions

• Before you begin, make sure you are partitioning the correct drive. For the rest of this tutorial, we will be using /dev/sdX as a placeholder.

root # lsblk
#NAME          MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
#sda             8:0    0  1.8T  0 disk 
#├─sdX1          8:1    0    1M  0 bios_boot
#├─sdX2          8:2    0    8G  0 esp      /efi
#└─sdX3          8:3    0  1.8T  0 part 
#  ├─main-root 254:0    0  500G  0 lvm  /
#  └─main-data 254:1    0  1.3T  0 lvm  /home

link your drive to /dev/sdX

to make following this guide easier you can set udev rules and link the drive you're installing to /dev/sdX so everything is copy paste. just replace the kernel's == sda/mmc/nvme to match your target drive.

• hda/sda drives:

root # echo 'KERNEL=="sda*", SYMLINK+="sdX%n"' > /etc/udev/rules.d/01-funtoo.rules
root # udevadm control --reload-rules
root # udevadm trigger

• mmc/nvme drives:

root # echo 'KERNEL=="mmcblk0", SYMLINK+="sdX"' > /etc/udev/rules.d/01-funtoo.rules
root # echo 'KERNEL=="mmcblk0p*", SYMLINK+="sdX%n"' >> /etc/udev/rules.d/01-funtoo.rules
root # udevadm control --reload-rules
root # udevadm trigger

• verify linking

root # ls -al /dev/sdX*
lrwxrwxrwx 1 root root 3 Jul 31 14:00 /dev/sdX -> sde
lrwxrwxrwx 1 root root 4 Jul 31 14:00 /dev/sdX1 -> sde1
lrwxrwxrwx 1 root root 4 Jul 31 14:00 /dev/sdX2 -> sde2

Partition

UEFI Partitioning

root # gdisk /dev/sdX

Within gdisk, follow these steps:

Empty the partition table:

Command: o ↵
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): y ↵

Create bios boot partition:

Command: n ↵
Partition Number: 1 ↵
First sector: ↵
Last sector: +1M ↵
Hex Code: EF02 ↵

Create efi esp partition:

Command: n ↵
Partition Number: 2 ↵
First sector: ↵
Last sector: +64M ↵
Hex Code: EF00 ↵

Create partition which will be encrypted with LUKS:

Command: n ↵
Partition Number: 3 ↵
First sector: ↵
Last sector: ↵ (for rest of disk)
Hex Code: ↵

Write Partition Table To Disk:

Command: w ↵
Do you want to proceed? (Y/N): Y ↵

The partition table will now be written to the disk and gdisk will close.

Create and mount filesystems.

Create esp filesystem

root # mkfs.vfat -F 32 /dev/sdX2

Create LUKS encrypted volume

   Warning

The debian-sources kernel in current stage3 tarballs does not allow for passwords in excess of 63 characters.

root # cryptsetup luksFormat --type luks1 /dev/sdX3

Open newly created LUKS volume

root # cryptsetup open /dev/sdX3 root

Create LVM volumes for / and swap

root # pvcreate /dev/mapper/root

root # vgcreate vg /dev/mapper/root

   Note

Replace "16G" with the amount of swap you would like to make available.

root # lvcreate -L16G --name swap vg

root # lvcreate -l 100%FREE --name root vg

   Note

The "-l 100%FREE" option above will use the remainder of the disk for your root partition. If you would prefer to create separate for /home or /var (for example), you can instead continue to use the "-LXXG" option for fixed sizes.

Create filesystems on LVM volumes

root # mkswap /dev/mapper/vg-swap

• for ext4:

root # mkfs.ext4 /dev/mapper/vg-root

• for xfs:

root # mkfs.xfs /dev/mapper/vg-root

Create directories for chroot

root # mkdir -p /mnt/funtoo

Mount filesystems

root # mount /dev/mapper/vg-root /mnt/funtoo

root # mkdir /mnt/funtoo/boot

root # mount /dev/sdX1 /mnt/funtoo/boot

root # mkdir /mnt/funtoo/proc

root # mount -t proc none /mnt/funtoo/proc

root # mkdir /mnt/funtoo/dev

root # mount --rbind /dev /mnt/funtoo/dev

root # mkdir /mnt/funtoo/sys

root # mount --rbind /sys /mnt/funtoo/sys

Set the date

   Note

See the official Funtoo docs on setting the date.

Install the Funtoo starge tarball of your choice

   Note

These instructions will be using the intel-haswell minimal stage3. You should adjust them accordingly

root # cd /mnt/funtoo

root # wget https://build.funtoo.org/1.4-release-std/x86-64bit/intel64-haswell/2021-03-10/stage3-intel64-haswell-1.4-release-std-2021-03-10.tar.xz

root # tar --numeric-owner --xattrs --xattrs-include='*' -xpf stage3-intel64-haswell-1.4-release-std-2021-03-10.tar.xz && rm -f stage3-intel64-haswell-1.4-release-std-2021-03-10.tar.xz

Chroot into your new system

root # env -i HOME=/root TERM=$TERM $(which chroot) /mnt/funtoo bash -l

Configure your system

Set a new root password

root # passwd

Set hostname

root # echo 'hostname="yourdesiredhostname"' > /etc/conf.d/hostname

Set up DNS resolution

   Note

We are using the Cloudflare DNS server address here. Feel free to use your own.

root # echo "nameserver 1.1.1.1" > /etc/resolv.conf

Set your timezone

root # ln -sf /usr/share/zoneinfo/$(tzselect) /etc/localtime

Note your filesystem information

root # blkid

/dev/sdX1: UUID="6453-0C55" TYPE="vfat" PARTLABEL="efi" PARTUUID="4e195c4b-f88c-4205-b9df-79a879704b2f"
/dev/sdX2: UUID="aafe709b-82e7-448f-a2cb-36adc3787dc3" TYPE="crypto_LUKS" PARTLABEL="system" PARTUUID="93d0cf9b-0b95-4d8b-919f-48cd1774996f"
/dev/mapper/root: UUID="hvz79n-I2VE-nR1c-0hDQ-PVkR-3GRb-rnuJ9C" TYPE="LVM2_member"
/dev/mapper/vg-swap: UUID="a9188bc3-7def-422b-990d-9de431825779" TYPE="swap"
/dev/mapper/vg-root: UUID="2eaf45e6-d33b-4155-b4ca-63a2fdbfb896" TYPE="ext4"

Configure /etc/fstab

   Note

The UUID parameter is set to the UUID of your boot partition as found from the blkid command above.

root # cat > /etc/fstab << 'EOF'
UUID=6453-0C55 /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
EOF

Create /etc/crypttab

   Note

The UUID parameter is set to the UUID of /dev/sdX2 as found from the blkid command above.

root # echo "root UUID=aafe709b-82e7-448f-a2cb-36adc3787dc3 none luks,discard" >> /etc/crypttab

Create /etc/dmtab

root # dmsetup table >> /etc/dmtab

Portage

Download the portage tree

root # ego sync

Change your ego profile to include encrypted root support

root # epro mix-in encrypted-root

Edit package USE-flags

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

Install necessary packages

root # emerge grub haveged intel-microcode linux-firmware cryptsetup lvm2 genkernel iucode_tool

Configure services to start at boot

root # rc-update add device-mapper sysinit

root # rc-update add dmcrypt sysinit

root # rc-update add lvmetad sysinit

root # rc-update add haveged default

root # rc-update add busybox-ntpd default

Install a bootloader

Configure /etc/boot.conf

   Note

The UUID parameter is set to the UUID of /dev/sdX2 as found from the blkid command above.

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=UUID=aafe709b-82e7-448f-a2cb-36adc3787dc3 dolvm real_root=/dev/mapper/vg-root ro rootfstype=ext4 resume=swap:/dev/mapper/vg-swap quiet
}
EOF

Install GRUB

For BIOS systems

root # grub-install --target=i386-pc --no-floppy /dev/sdX

root # ego boot update

For UEFI systems

root # mount -o remount,rw /sys/firmware/efi/efivars

   Note

For 32 bit systems, the following command should be changed to:

root # grub-install --target=i386-efi --efi-directory=/boot --bootloader-id="Funtoo Linux" --recheck /dev/sdX

root # grub-install --target=x86_64-efi --efi-directory=/boot --bootloader-id="Funtoo Linux" --recheck /dev/sdX

root # ego boot update

Generate a new initramfs

root # genkernel --clean --luks --lvm --disklabel --ramdisk-modules --fullname=$(ls /boot/initramfs-* | tail -c +17) initramfs

Finishing installation

From this point, you should be able to finish following the official Funtoo Linux install instructions

Managing your LUKS volume

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