ZFS mirror ubuntu boot drive

mirror.sh

#!/bin/sh

# Assumptions and requirements
# - All drives will be formatted. These instructions are not suitable for dual-boot
# - No hardware or software RAID is to be used, these would keep ZFS from detecting disk errors and correcting them. In UEFI settings, set controller mode to AHCI, not RAID
# - These instructions are specific to UEFI systems and GPT. If you have an older BIOS/MBR system, please use https://openzfs.github.io/openzfs-docs/Getting%20Started/Ubuntu/Ubuntu%2020.04%20Root%20on%20ZFS.html

# change the these disks variables to your disks paths (check with  lsblk)
DISK1="/dev/nvme0n1"
DISK2="/dev/nvme1n1"

if [ "$(id -u)" -ne 0 ]; then
    echo "Please run this script with sudo:"
    echo "sudo $0 $*"
    exit 1
fi

echo "Installing dependencies"
apt install -y gdisk mdadm grub-efi-amd64

echo "-- Create partitions on second drive"

echo "Change swap partition type"
sgdisk -t2:FD00 $DISK1

echo "Copy partition table from disk 1 to disk 2"
sgdisk -R $DISK2 $DISK1

echo "Change GUID of second disk"
sgdisk -G $DISK2

# this change seems to take a while to propagate :/
sleep 1

echo "-- Mirror boot pool"

echo "Get GUID of partition 3 on disk 2"
DISK1_PART3_GUID=$(sgdisk -i3 $DISK1 |  grep "^Partition unique GUID:" | awk '{print tolower($4)}')
DISK2_PART3_GUID=$(sgdisk -i3 $DISK2 |  grep "^Partition unique GUID:" | awk '{print tolower($4)}')
echo "DISK 1 PART 3 GUID"
echo $DISK1_PART3_GUID
echo "DISK 2 PART 3 GUID"
echo $DISK2_PART3_GUID

if [ -z  $DISK1_PART3_GUID ]; then
    echo "error: failed to get the disk1 part 3 guid"
    exit 1
fi

if [ -z  $DISK2_PART3_GUID ]; then
    echo "error: failed to get the disk2 part 3 guid"
    exit 1
fi

echo "attach partition to bpool"
zpool attach bpool $DISK1_PART3_GUID /dev/disk/by-partuuid/$DISK2_PART3_GUID || exit 1

# TODO: check for failure here by the zpool status not showing the mirror

echo "-- Mirror root pool"

DISK1_PART4_GUID=$(sgdisk -i4 $DISK1 |  grep "^Partition unique GUID:" | awk '{print tolower($4)}')
DISK2_PART4_GUID=$(sgdisk -i4 $DISK2 |  grep "^Partition unique GUID:" | awk '{print tolower($4)}')

if [ -z  $DISK1_PART4_GUID ]; then
    echo "error: failed to get the disk1 part 4 guid"
    exit 1
fi

if [ -z  $DISK2_PART4_GUID ]; then
    echo "error: failed to get the disk2 part 4 guid"
    exit 1
fi

echo "attach partition to rpool"
zpool attach rpool $DISK1_PART4_GUID /dev/disk/by-partuuid/$DISK2_PART4_GUID || exit 1

# TODO: check for failure here by the zpool status not showing the mirror

echo "-- Mirror Swap"

echo "remove existing swap"
swapoff -a || exit 1

echo "remove the swap mount line in /etc/fstab"
sed -i '/swap/d' /etc/fstab

echo "create software mirror drive for swap"
mdadm --create /dev/md0 --metadata=1.2 --level=mirror --raid-devices=2 ${DISK1}p2 ${DISK2}p2 || exit 1

echo "configure mirror drive for swap"
mkswap -f /dev/md0 || exit 1

echo "place mirror swap in fstab"
sh -c "echo UUID=$(sudo blkid -s UUID -o value /dev/md0) none swap discard 0 0 >> /etc/fstab"

# TODO: verify that line is in fstab cat /etc/fstab

echo "use the new swap"
swapon -a || exit 1

echo "-- Move grub menu to ZFS"

# TODO: verify that grub can  see the ZFS boot pool grub-probe /boot

echo "create EFI file system on second disk"
mkdosfs -F 32 -s 1 -n EFI ${DISK2}p1

echo "remove /boot/grub from fstab"
sed -i '/grub/d' /etc/fstab

echo "umount /boot/grub"
umount /boot/grub

# TODO: Verify with df -h, /boot should be mounted on bpool/BOOT/ubuntu_UID, /boot/efi on /dev/sda1 or similar depending on device name of your first disk, and no /boot/grub

echo "remove /boot/grub"
rm -rf /boot/grub

echo "create ZFS datatset for grub"
zfs create -o com.ubuntu.zsys:bootfs=no bpool/grub

echo "refresh initrd files"
update-initramfs -c -k all

echo "disable memory zeroing to address a performance regression of ZFS on linux"
sed -i.bak "s/GRUB_CMDLINE_LINUX_DEFAULT=\"quiet splash\"/GRUB_CMDLINE_LINUX_DEFAULT=\"quiet splash init_on_alloc=0\"/g" /etc/default/grub

echo "update grub"
update-grub

echo "reload daemon"
systemctl daemon-reload

echo "install grub to the esp"
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=ubuntu --recheck --no-floppy

echo "disable grub-initrd-fallback.service"
systemctl mask grub-initrd-fallback.service

echo "DONE without errors"

dpkg-reconfigure grub-efi-amd64

Not tested but looks good, thanks!

If you publish it on GitHub as a repo instead one could contribute * hint hint * :)

@enoch85 noted, will make it to a repo after I do more testing on it, don't think its very stable 🍂

Whats the status on that? Is it verified to be working well?

my Ubuntu 22.04 ZFS installation using the Ubuntu installer has 5 partitions on the disk, not 4. They are p1 1024K EF02 , p2 513K EF00, p3 2G 8200, p4 2G BE00 and p5 949G BF00. P5 is the rpool, p4 is the bpool, p3 is swap, p2 is EFI System Partition and p1 is BIOS boot. I can't copy this disk to another of the same size using sgdisk -R disk2 disk1.

I found on Ubuntu 22.04 that this needs a few changes.

1. The partition indicator on line 107 (p1) should be -part1 for 22.04
2. The partitition indicators on line 89 (p2 twice) should be -part2 for 22.04
3. Benefits from partprobe around line 34 to update the OS state of the partition table