Setting up Encrypted Ubuntu 18.10 ZFS Desktop

I have already explained how I deal with ZFS mirror setup on Ubuntu 18.10. But what about laptops that generally come with a single drive?

Well, as before basic instructions are available from ZFS-on-Linux project. However, they do have a certain way of doing things I don’t necessarily subscribe to. Here is my way of setting this up. As always, it’s best to setup remote access so you can copy/paste as steps are numerous.

As before, we first need to get into root prompt:

$ sudo -i

Followed by getting a few basic packages ready:

# apt-add-repository universe
# apt update
# apt install --yes debootstrap gdisk zfs-initramfs

We setup disks essentially the same way as in previous guide:

# sgdisk --zap-all                 /dev/disk/by-id/ata_disk

# sgdisk -a1 -n3:34:2047  -t3:EF02 /dev/disk/by-id/ata_disk
# sgdisk     -n2:1M:+511M -t2:8300 /dev/disk/by-id/ata_disk
# sgdisk     -n1:0:0      -t1:8300 /dev/disk/by-id/ata_disk

# sgdisk --print                   /dev/disk/by-id/ata_disk

Number  Start (sector)    End (sector)  Size       Code  Name
   1         1050624        67108830   31.5 GiB    8300
   2            2048         1050623   512.0 MiB   8300
   3              34            2047   1007.0 KiB  EF02

Because we want encryption, we need to setup LUKS:

# cryptsetup luksFormat -qc aes-xts-plain64 -s 256 -h sha256 /dev/disk/by-id/ata_disk-part1
# cryptsetup luksOpen /dev/disk/by-id/ata_disk-part1 luks1

Unlike in the last guide, this time I want to have a bit of separation. Dataset system will contain the whole system, while data will contain only the home directories. Again, if you want to split it all, follow the original guide:

# zpool create -o ashift=12 -O atime=off -O canmount=off -O compression=lz4 -O normalization=formD \
      -O xattr=sa -O mountpoint=none rpool /dev/mapper/luks1
# zfs create -o canmount=noauto -o mountpoint=/mnt/rpool/ rpool/system
# zfs mount rpool/system

We should also setup the boot partition:

# mke2fs -Ft ext2 /dev/disk/by-id/ata_disk-part2
# mkdir /mnt/rpool/boot/
# mount /dev/disk/by-id/ata_disk-part2 /mnt/rpool/boot/

Now we can get basic installation on out disks:

# debootstrap cosmic /mnt/rpool/
# zfs set devices=off rpool
# zfs list

Before we start using it, we prepare few necessary files:

# cp /etc/hostname /mnt/rpool/etc/hostname
# cp /etc/hosts /mnt/rpool/etc/hosts
# cp /etc/netplan/*.yaml /mnt/rpool/etc/netplan/
# sed '/cdrom/d' /etc/apt/sources.list > /mnt/rpool/etc/apt/sources.list

With chroot we can get the first taste of our new system:

# mount --rbind /dev  /mnt/rpool/dev
# mount --rbind /proc /mnt/rpool/proc
# mount --rbind /sys  /mnt/rpool/sys
# chroot /mnt/rpool/ /bin/bash --login

Now we can update our software and perform locale and time zone setup:

# apt update

# locale-gen --purge "en_US.UTF-8"
# update-locale LANG=en_US.UTF-8 LANGUAGE=en_US
# dpkg-reconfigure --frontend noninteractive locales

# dpkg-reconfigure tzdata

Now we install Linux image and basic ZFS boot packages:

# apt install --yes --no-install-recommends linux-image-generic
# apt install --yes zfs-initramfs

Since we’re dealing with encrypted data, our cryptsetup should be also auto mounted:

# apt install --yes cryptsetup

# echo "luks1 UUID=$(blkid -s UUID -o value /dev/disk/by-id/ata_disk-part1) none luks,discard,initramfs" >> /etc/crypttab
# cat /etc/crypttab

And of course, we need to auto-mount our boot partition too:

# echo "UUID=$(blkid -s UUID -o value /dev/disk/by-id/ata_disk-part2) /boot ext2 noatime 0 2" >> /etc/fstab
# cat /etc/fstab

Now we get grub started (do select the WHOLE disk):

# apt install --yes grub-pc

And update our boot environment again (seeing errors is nothing unusual):

# update-initramfs -u -k all

And then we finalize our grup setup:

# update-grub
# grub-install /dev/disk/by-id/ata_disk

Finally we get the rest of desktop system:

# apt-get install --yes ubuntu-desktop samba linux-headers-generic
# apt dist-upgrade --yes

We can omit creation of the swap dataset but I always find it handy:

# zfs create -V 4G -b $(getconf PAGESIZE) -o compression=off -o logbias=throughput -o sync=always \
      -o primarycache=metadata -o secondarycache=none rpool/swap
# mkswap -f /dev/zvol/rpool/swap
# echo "/dev/zvol/rpool/swap none swap defaults 0 0" >> /etc/fstab
# echo RESUME=none > /etc/initramfs-tools/conf.d/resume

And now is good time to swap our /home directory too:

# rmdir /home
# zfs create -o mountpoint=/home rpool/data

Now we are ready to create the user:

# adduser -u 1002 user
# usermod -a -G adm,cdrom,dip,lpadmin,plugdev,sambashare,sudo user
# chown -R user:user /home/user

Lastly we exit our chroot environment and reboot:

# exit
# reboot

You will get stuck after the password prompt as our mountpoint for system dataset is wrong. That’s easy to correct:

# zfs set mountpoint=/ rpool/system
# exit
# reboot

Assuming nothing went wrong, your system is now ready.

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