.. highlight:: sh Arch Linux Root on ZFS ====================== .. contents:: Table of Contents :local: Overview -------- Caution ~~~~~~~ - This guide uses entire physical disks. - Multiple systems on one disk is not supported. - Target disk will be wiped. Back up your data before continuing. - The target system, virtual or physical, must have at least 4GB RAM, or the DKMS module might fail to build. - Installing on a drive which presents 4 KiB logical sectors (a “4Kn” drive) only works with UEFI booting. This not unique to ZFS. `GRUB does not and will not work on 4Kn with legacy (BIOS) booting. `__ Support ~~~~~~~ If you need help, reach out to the community using the :ref:`mailing_lists` or IRC at `#zfsonlinux `__ on `freenode `__. If you have a bug report or feature request related to this HOWTO, please `file a new issue and mention @ne9z `__. Contributing ~~~~~~~~~~~~ #. Fork and clone `this repo `__. #. Install the tools:: sudo pacman -S python-pip pip3 install -r docs/requirements.txt # Add ~/.local/bin to your $PATH, e.g. by adding this to ~/.bashrc: PATH=$HOME/.local/bin:$PATH #. Make your changes. #. Test:: cd docs make html sensible-browser _build/html/index.html #. ``git commit --signoff`` to a branch, ``git push``, and create a pull request. Mention @rlaager. Encryption ~~~~~~~~~~ This guide supports optional ZFS native encryption on root pool. Unencrypted does not encrypt anything, of course. With no encryption happening, this option naturally has the best performance. ZFS native encryption encrypts the data and most metadata in the root pool. It does not encrypt dataset or snapshot names or properties. The boot pool is not encrypted at all, but it only contains the bootloader, kernel, and initrd. (Unless you put a password in ``/etc/fstab``, the initrd is unlikely to contain sensitive data.) The system cannot boot without the passphrase being entered at the console. Performance is good. As the encryption happens in ZFS, even if multiple disks (mirror or raidz topologies) are used, the data only has to be encrypted once. Boot pool can be optionally encrypted with LUKS, see `here <#encrypt-boot-pool-with-luks>`__. Encrypted boot pool can protect initrd from tempering. Preinstallation ---------------- Download Arch Linux live image ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. Choose a mirror `Mirrorlist `__ #. Download Feb 2021 build and signature. `File a new issue and mention @ne9z `__ if it's no longer available. - `ISO (US mirror) `__ - `Signature `__ #. Check live image against signature:: gpg --auto-key-retrieve --verify archlinux-2021.02.01-x86_64.iso.sig If the file is authentic, output should be the following:: gpg: Signature made Mon 01 Feb 2021 03:23:39 PM UTC gpg: using RSA key 4AA4767BBC9C4B1D18AE28B77F2D434B9741E8AC gpg: Good signature from "Pierre Schmitz " [unknown] ... Primary key fingerprint: 4AA4 767B BC9C 4B1D 18AE 28B7 7F2D 434B 9741 E8AC Ensure ``Good signature`` and last 8 digits are ``9741 E8AC``, as listed on `Arch Linux Developers `__ page. #. Write the image to a USB drive or an optical disc. #. Boot the target computer from the prepared live medium. Prepare the Live Environment ~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. Connect to the internet. If the target computer aquires IP address with DHCP, no further steps need to be taken. Otherwise, refer to `Network Configuration `__ wiki page. #. Start SSH server. - Interactively set root password with:: passwd - Start SSH server:: systemctl start sshd - Find the IP address of the target computer:: ip -4 address show scope global - On another computer, connect to the target computer with:: ssh root@192.168.1.10 #. Enter a bash shell:: bash #. Import keys of archzfs repository:: curl -L https://archzfs.com/archzfs.gpg | pacman-key -a - curl -L https://git.io/JtQpl | xargs -i{} pacman-key --lsign-key {} #. Add archzfs repository:: tee -a /etc/pacman.conf <<- 'EOF' [archzfs] Include = /etc/pacman.d/mirrorlist-archzfs EOF curl -L https://git.io/JtQp4 > /etc/pacman.d/mirrorlist-archzfs #. Select mirror: - Kill ``reflector``:: killall -9 reflector - Edit the following files:: nano /etc/pacman.d/mirrorlist Uncomment and move mirrors to the beginning of the file. - Update database:: pacman -Sy #. Install ZFS in the live environment: Check kernel variant:: LIVE_LINVAR=$(sed 's|.*linux|linux|' /proc/cmdline | sed 's|.img||g' | awk '{ print $1 }') Check kernel version:: LIVE_LINVER=$(pacman -Qi ${LIVE_LINVAR} | grep Version | awk '{ print $3 }') Install kernel headers:: pacman -U https://archive.archlinux.org/packages/l/${LIVE_LINVAR}-headers/${LIVE_LINVAR}-headers-${LIVE_LINVER}-x86_64.pkg.tar.zst Expand root filesystem:: mount -o remount,size=2G /run/archiso/cowspace Install zfs-dkms:: pacman -S zfs-dkms glibc #. Load kernel module:: modprobe zfs Installation Variables ~~~~~~~~~~~~~~~~~~~~~~~~~~~ In this part, we will set some variables to configure the system. #. Timezone List the available timezones with:: ls /usr/share/zoneinfo/ Store the target timezone in a variable:: INST_TZ=/usr/share/zoneinfo/Asia/Irkutsk #. Host name Store the host name in a variable:: INST_HOST='localhost' #. Kernel variant Store the kernel variant in a variable. Available variants in official repo are: - linux - linux-lts - linux-zen - linux-hardened :: INST_LINVAR='linux' #. Target disk List the available disks with:: ls -d /dev/disk/by-id/* | grep -v part If the disk is not in the command output, use ``/dev/disk/by-path``. Store the target disk in a variable:: DISK=/dev/disk/by-id/nvme-foo_NVMe_bar_512GB For multi-disk setups, repeat the formatting and partitioning commands for other disks. #. Create a mountpoint with:: INST_MNT=$(mktemp -d) #. To avoid name conflict when importing pools on another computer, Give them a unique suffix:: INST_UUID=$(dd if=/dev/urandom of=/dev/stdout bs=1 count=100 2>/dev/null |tr -dc 'a-z0-9' | cut -c-6) System Installation ------------------- Format and Partition the Target Disks ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. Clear the partition table:: sgdisk --zap-all $DISK #. Create EFI system partition (for use now or in the future):: sgdisk -n1:1M:+1G -t1:EF00 $DISK #. Create BIOS boot partition:: sgdisk -a1 -n5:24K:+1000K -t5:EF02 $DISK #. Create boot pool partition:: sgdisk -n2:0:+4G -t2:BE00 $DISK #. Create root pool partition: - If you don't need a separate swap partition:: sgdisk -n3:0:0 -t3:BF00 $DISK - If a separate swap partition is needed:: sgdisk -n3:0:-8G -t3:BF00 $DISK sgdisk -n4:0:0 -t4:8308 $DISK Adjust the swap partition size to your needs. If `hibernation <#hibernation>`__ is needed, swap size should be same or larger than RAM. Check RAM size with ``free -h``. #. Repeat the above steps for other target disks, if any. Create Root and Boot Pools ~~~~~~~~~~~~~~~~~~~~~~~~~~ #. For multi-disk setup If you want to create a multi-disk pool, replace ``${DISK}-partX`` with the topology and the disk path. For example, change:: zpool create \ ... \ ${DISK}-part2 to:: zpool create \ ... \ mirror \ /dev/disk/by-id/ata-disk1-part2 \ /dev/disk/by-id/ata-disk2-part2 if needed, replace ``mirror`` with ``raidz1``, ``raidz2`` or ``raidz3``. #. Create boot pool:: zpool create \ -o ashift=12 \ -o autotrim=on \ -d -o feature@async_destroy=enabled \ -o feature@bookmarks=enabled \ -o feature@embedded_data=enabled \ -o feature@empty_bpobj=enabled \ -o feature@enabled_txg=enabled \ -o feature@extensible_dataset=enabled \ -o feature@filesystem_limits=enabled \ -o feature@hole_birth=enabled \ -o feature@large_blocks=enabled \ -o feature@lz4_compress=enabled \ -o feature@spacemap_histogram=enabled \ -O acltype=posixacl \ -O canmount=off \ -O compression=lz4 \ -O devices=off \ -O normalization=formD \ -O relatime=on \ -O xattr=sa \ -O mountpoint=/boot \ -R $INST_MNT \ bpool_$INST_UUID \ ${DISK}-part2 You should not need to customize any of the options for the boot pool. GRUB does not support all of the zpool features. See ``spa_feature_names`` in `grub-core/fs/zfs/zfs.c `__. This step creates a separate boot pool for ``/boot`` with the features limited to only those that GRUB supports, allowing the root pool to use any/all features. Note that GRUB opens the pool read-only, so all read-only compatible features are “supported” by GRUB. **Feature Notes:** - The ``allocation_classes`` feature should be safe to use. However, unless one is using it (i.e. a ``special`` vdev), there is no point to enabling it. It is extremely unlikely that someone would use this feature for a boot pool. If one cares about speeding up the boot pool, it would make more sense to put the whole pool on the faster disk rather than using it as a ``special`` vdev. - The ``project_quota`` feature has been tested and is safe to use. This feature is extremely unlikely to matter for the boot pool. - The ``resilver_defer`` should be safe but the boot pool is small enough that it is unlikely to be necessary. - The ``spacemap_v2`` feature has been tested and is safe to use. The boot pool is small, so this does not matter in practice. - As a read-only compatible feature, the ``userobj_accounting`` feature should be compatible in theory, but in practice, GRUB can fail with an “invalid dnode type” error. This feature does not matter for ``/boot`` anyway. #. Create root pool:: zpool create \ -o ashift=12 \ -o autotrim=on \ -R $INST_MNT \ -O acltype=posixacl \ -O canmount=off \ -O compression=zstd \ -O dnodesize=auto \ -O normalization=formD \ -O relatime=on \ -O xattr=sa \ -O mountpoint=/ \ rpool_$INST_UUID \ ${DISK}-part3 **Notes:** - The use of ``ashift=12`` is recommended here because many drives today have 4 KiB (or larger) physical sectors, even though they present 512 B logical sectors. Also, a future replacement drive may have 4 KiB physical sectors (in which case ``ashift=12`` is desirable) or 4 KiB logical sectors (in which case ``ashift=12`` is required). - Setting ``-O acltype=posixacl`` enables POSIX ACLs globally. If you do not want this, remove that option, but later add ``-o acltype=posixacl`` (note: lowercase “o”) to the ``zfs create`` for ``/var/log``, as `journald requires ACLs `__ - Setting ``normalization=formD`` eliminates some corner cases relating to UTF-8 filename normalization. It also implies ``utf8only=on``, which means that only UTF-8 filenames are allowed. If you care to support non-UTF-8 filenames, do not use this option. For a discussion of why requiring UTF-8 filenames may be a bad idea, see `The problems with enforced UTF-8 only filenames `__. - ``recordsize`` is unset (leaving it at the default of 128 KiB). If you want to tune it (e.g. ``-o recordsize=1M``), see `these `__ `various `__ `blog `__ `posts `__. - Setting ``relatime=on`` is a middle ground between classic POSIX ``atime`` behavior (with its significant performance impact) and ``atime=off`` (which provides the best performance by completely disabling atime updates). Since Linux 2.6.30, ``relatime`` has been the default for other filesystems. See `RedHat’s documentation `__ for further information. - Setting ``xattr=sa`` `vastly improves the performance of extended attributes `__. Inside ZFS, extended attributes are used to implement POSIX ACLs. Extended attributes can also be used by user-space applications. `They are used by some desktop GUI applications. `__ `They can be used by Samba to store Windows ACLs and DOS attributes; they are required for a Samba Active Directory domain controller. `__ Note that ``xattr=sa`` is `Linux-specific `__. If you move your ``xattr=sa`` pool to another OpenZFS implementation besides ZFS-on-Linux, extended attributes will not be readable (though your data will be). If portability of extended attributes is important to you, omit the ``-O xattr=sa`` above. Even if you do not want ``xattr=sa`` for the whole pool, it is probably fine to use it for ``/var/log``. - Make sure to include the ``-part3`` portion of the drive path. If you forget that, you are specifying the whole disk, which ZFS will then re-partition, and you will lose the bootloader partition(s). - ZFS native encryption `now `__ defaults to ``aes-256-gcm``. - Your passphrase will likely be the weakest link. Choose wisely. See `section 5 of the cryptsetup FAQ `__ for guidance. Create Datasets ~~~~~~~~~~~~~~~~~~~~~~ #. Create system boot container:: zfs create \ -o canmount=off \ -o mountpoint=/boot \ bpool_$INST_UUID/sys #. Create system root container: Dataset encryption is set at creation and can not be altered later, but encrypted dataset can be created inside an unencrypted parent dataset. - Unencrypted:: zfs create \ -o canmount=off \ -o mountpoint=/ \ rpool_$INST_UUID/sys - Encrypted: #. Choose a strong password. Once the password is compromised, dataset and pool must be destroyed, disk wiped and system rebuilt from scratch to protect confidentiality. `Merely changing password is not enough `__. Example: generate passphrase with `xkcdpass `_:: pacman -S --noconfirm xkcdpass xkcdpass -Vn 10 -w /usr/lib/python*/site-packages/xkcdpass/static/eff-long Password can be supplied with SSH at boot time, see `Supply password with SSH <#supply-password-with-ssh>`__. #. Create dataset:: zfs create \ -o canmount=off \ -o mountpoint=/ \ -o encryption=on \ -o keylocation=prompt \ -o keyformat=passphrase \ rpool_$INST_UUID/sys #. Create container datasets:: zfs create -o canmount=off -o mountpoint=none bpool_$INST_UUID/sys/BOOT zfs create -o canmount=off -o mountpoint=none rpool_$INST_UUID/sys/ROOT zfs create -o canmount=off -o mountpoint=none rpool_$INST_UUID/sys/DATA #. Create root and boot filesystem datasets:: zfs create -o mountpoint=legacy -o canmount=noauto bpool_$INST_UUID/sys/BOOT/default zfs create -o mountpoint=/ -o canmount=noauto rpool_$INST_UUID/sys/ROOT/default #. Mount root and boot filesystem datasets:: zfs mount rpool_$INST_UUID/sys/ROOT/default mkdir $INST_MNT/boot mount -t zfs bpool_$INST_UUID/sys/BOOT/default $INST_MNT/boot #. Create datasets to separate user data from root filesystem:: zfs create -o mountpoint=/ -o canmount=off rpool_$INST_UUID/sys/DATA/default for i in {usr,var,var/lib}; do zfs create -o canmount=off rpool_$INST_UUID/sys/DATA/default/$i done for i in {home,root,srv,usr/local,var/log,var/spool,var/tmp}; do zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/$i done chmod 750 $INST_MNT/root chmod 1777 $INST_MNT/var/tmp #. Optional user data datasets: If this system will have games installed:: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/games If you use /var/www on this system:: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/www If this system will use GNOME:: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/lib/AccountsService If this system will use Docker (which manages its own datasets & snapshots):: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/lib/docker If this system will use NFS (locking):: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/lib/nfs If this system will use Linux Containers:: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/lib/lxc If this system will use libvirt:: zfs create -o canmount=on rpool_$INST_UUID/sys/DATA/default/var/lib/libvirt Format and Mount EFI System Partition ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ :: mkfs.vfat -n EFI ${DISK}-part1 mkdir $INST_MNT/boot/efi mount -t vfat ${DISK}-part1 $INST_MNT/boot/efi If you are using a multi-disk setup, this step will only install bootloader to the first disk. Other disks will be handled later. Package Installation ~~~~~~~~~~~~~~~~~~~~ #. Install base packages:: pacstrap $INST_MNT base vi mandoc grub #. Check compatible kernel version:: INST_LINVER=$(pacman -Si zfs-${INST_LINVAR} \ | grep 'Depends On' \ | sed "s|.*${INST_LINVAR}=||" \ | awk '{ print $1 }') #. Install kernel. Download from archive if kernel is not available:: if [ ${INST_LINVER} == \ $(pacman -Si ${INST_LINVAR} | grep Version | awk '{ print $3 }') ]; then pacstrap $INST_MNT ${INST_LINVAR} else pacstrap -U $INST_MNT \ https://archive.archlinux.org/packages/l/${INST_LINVAR}/${INST_LINVAR}-${INST_LINVER}-x86_64.pkg.tar.zst fi #. Install archzfs package:: pacstrap $INST_MNT zfs-$INST_LINVAR #. Install firmware:: pacstrap $INST_MNT linux-firmware intel-ucode amd-ucode #. If you boot your computer with EFI:: pacstrap $INST_MNT efibootmgr #. For other optional packages, see `ArchWiki `__. System Configuration -------------------- #. Generate list of datasets for ``zfs-mount-generator`` to mount them at boot:: # tab-separated zfs properties # see /etc/zfs/zed.d/history_event-zfs-list-cacher.sh export \ PROPS="name,mountpoint,canmount,atime,relatime,devices,exec\ ,readonly,setuid,nbmand,encroot,keylocation\ ,org.openzfs.systemd:requires,org.openzfs.systemd:requires-mounts-for\ ,org.openzfs.systemd:before,org.openzfs.systemd:after\ ,org.openzfs.systemd:wanted-by,org.openzfs.systemd:required-by\ ,org.openzfs.systemd:nofail,org.openzfs.systemd:ignore" mkdir -p $INST_MNT/etc/zfs/zfs-list.cache zfs list -H -t filesystem -o $PROPS -r rpool_$INST_UUID > $INST_MNT/etc/zfs/zfs-list.cache/rpool_$INST_UUID sed -Ei "s|$INST_MNT/?|/|" $INST_MNT/etc/zfs/zfs-list.cache/* #. Generate fstab:: echo bpool_$INST_UUID/sys/BOOT/default /boot zfs rw,xattr,posixacl 0 0 >> $INST_MNT/etc/fstab echo UUID=$(blkid -s UUID -o value ${DISK}-part1) /boot/efi vfat \ x-systemd.idle-timeout=1min,x-systemd.automount,noauto,umask=0022,fmask=0022,dmask=0022 0 1 >> $INST_MNT/etc/fstab If a swap partition has been created:: echo crypt-swap ${DISK}-part4 /dev/urandom swap,cipher=aes-cbc-essiv:sha256,size=256,discard >> $INST_MNT/etc/crypttab echo /dev/mapper/crypt-swap none swap defaults 0 0 >> $INST_MNT/etc/fstab #. Configure mkinitcpio:: mv $INST_MNT/etc/mkinitcpio.conf $INST_MNT/etc/mkinitcpio.conf.original tee $INST_MNT/etc/mkinitcpio.conf < $INST_MNT/etc/hostname #. Configure the network interface: Find the interface name:: ip link Store it in a variable:: INET=enp1s0 Create network configuration:: tee $INST_MNT/etc/systemd/network/20-default.network <`__. #. Timezone:: ln -sf $INST_TZ $INST_MNT/etc/localtime hwclock --systohc #. Locale:: echo "en_US.UTF-8 UTF-8" >> $INST_MNT/etc/locale.gen echo "LANG=en_US.UTF-8" >> $INST_MNT/etc/locale.conf Other locales should be added after reboot. #. Chroot:: arch-chroot $INST_MNT /usr/bin/env DISK=$DISK INST_UUID=$INST_UUID bash --login #. Apply locales:: locale-gen #. Import keys of archzfs repository:: curl -L https://archzfs.com/archzfs.gpg | pacman-key -a - curl -L https://git.io/JtQpl | xargs -i{} pacman-key --lsign-key {} #. Add archzfs repository:: tee -a /etc/pacman.conf <<- 'EOF' [archzfs] Include = /etc/pacman.d/mirrorlist-archzfs EOF curl -L https://git.io/JtQp4 > /etc/pacman.d/mirrorlist-archzfs #. Enable networking:: systemctl enable systemd-networkd systemd-resolved #. Enable ZFS services:: systemctl enable zfs-import-cache zfs-import.target zfs-mount zfs-zed zfs.target #. Generate zpool.cache Pools are imported by initramfs with the information stored in ``/etc/zfs/zpool.cache``. This cache file will be embedded in initramfs. :: zpool set cachefile=/etc/zfs/zpool.cache rpool_$INST_UUID zpool set cachefile=/etc/zfs/zpool.cache bpool_$INST_UUID #. Set root password:: passwd #. Generate initramfs:: mkinitcpio -P Bootloader Installation ---------------------------- Currently GRUB has multiple compatibility problems with ZFS, especially with regards to newer ZFS features. Workarounds have to be applied. grub-probe fails to get canonical path ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ When persistent device names ``/dev/disk/by-id/*`` are used with ZFS, GRUB will fail to resolve the path of the boot pool device. Error:: # /usr/bin/grub-probe: error: failed to get canonical path of `/dev/virtio-pci-0000:06:00.0-part3'. Solution:: echo 'export ZPOOL_VDEV_NAME_PATH=YES' >> /etc/profile source /etc/profile Pool name missing ~~~~~~~~~~~~~~~~~ See `this bug report `__. Root pool name is missing from ``root=ZFS=rpool/ROOT/default`` in generated ``grub.cfg`` file. A workaround is to replace the pool name detection with ``zdb`` command:: sed -i "s|rpool=.*|rpool=\`zdb -l \${GRUB_DEVICE} \| grep -E '[[:blank:]]name' \| cut -d\\\' -f 2\`|" /etc/grub.d/10_linux If you forgot to apply this workaround and followed this guide to use ``rpool_$INST_UUID`` and ``bpool_$INST_UUID``, ``$INST_UUID`` can be found out with `Load grub.cfg in GRUB command line`_. GRUB Installation ~~~~~~~~~~~~~~~~~ - If you use EFI:: grub-install This will only install boot loader to $DISK. If you use multi-disk setup, other disks are dealt with later. Some motherboards does not properly recognize GRUB boot entry, to ensure that your computer will boot, also install GRUB to fallback location with:: grub-install --removable - If you use BIOS booting:: grub-install $DISK If this is a multi-disk setup, install to other disks as well:: for i in {target_disk2,target_disk3}; do grub-install /dev/disk/by-id/$i done Generate GRUB Boot Menu ~~~~~~~~~~~~~~~~~~~~~~~ :: grub-mkconfig -o /boot/grub/grub.cfg Optional Configuration ---------------------- Supply password with SSH ~~~~~~~~~~~~~~~~~~~~~~~~ Optional: #. Install mkinitcpio tools:: pacman -S mkinitcpio-netconf mkinitcpio-dropbear openssh #. Store public keys in ``/etc/dropbear/root_key``:: vi /etc/dropbear/root_key Note that dropbear only supports RSA keys. #. Edit mkinitcpio:: tee /etc/mkinitcpio.conf <<- 'EOF' HOOKS=(base udev autodetect modconf block keyboard netconf dropbear zfsencryptssh zfs filesystems) EOF #. Add ``ip=`` to kernel command line:: # example DHCP echo 'GRUB_CMDLINE_LINUX="ip=::::::dhcp"' >> /etc/default/grub Details for ``ip=`` can be found at `here `__. #. Generate host keys:: ssh-keygen -Am pem #. Regenerate initramfs:: mkinitcpio -P #. Update GRUB menu:: grub-mkconfig -o /boot/grub/grub.cfg Finish Installation ------------------- #. Exit chroot:: exit #. Take a snapshot of the clean installation for future use:: zfs snapshot -r rpool_$INST_UUID/sys/ROOT/default@install zfs snapshot -r bpool_$INST_UUID/sys/BOOT/default@install #. Unmount EFI system partition:: umount $INST_MNT/boot/efi #. Export pools:: zpool export bpool_$INST_UUID zpool export rpool_$INST_UUID They must be exported, or else they will fail to be imported on reboot. After Reboot ------------ Mirror EFI System Partition ~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. Check disk name:: ls -1 /dev/disk/by-id/ | grep -v '\-part[0-9]' #. Mirror EFI ssystem partition:: for i in {target_disk2,target_disk3}; do mkfs.vfat /dev/disk/by-id/$i-part1 mkdir -p /boot/efis/$i echo UUID=$(blkid -s UUID -o value /dev/disk/by-id/$i-part1) /boot/efis/$i vfat \ x-systemd.idle-timeout=1min,x-systemd.automount,noauto,umask=0022,fmask=0022,dmask=0022 \ 0 1 >> /etc/fstab mount /boot/efis/$i cp -r /boot/efi/EFI/ /boot/efis/$i efibootmgr -cgp 1 -l "\EFI\arch\grubx64.efi" \ -L "arch-$i" -d /dev/disk/by-id/$i-part1 done #. Create a service to monitor and sync EFI partitions:: tee /etc/systemd/system/efis-sync.path << EOF [Unit] Description=Monitor changes in EFI system partition [Path] PathChanged=/boot/efi/EFI/arch/ #PathChanged=/boot/efi/EFI/BOOT/ [Install] WantedBy=multi-user.target EOF tee /etc/systemd/system/efis-sync.service << EOF [Unit] Description=Sync EFI system partition contents to backups [Service] Type=oneshot ExecStart=/usr/bin/bash -c 'for i in /boot/efis/*; do /usr/bin/cp -r /boot/efi/EFI/ $i/; done' EOF systemctl enable --now efis-sync.path #. If EFI system partition failed, promote one backup to ``/boot/efi`` by editing ``/etc/fstab``. Mirror BIOS boot sector ~~~~~~~~~~~~~~~~~~~~~~~ This need to be manually applied when GRUB is updated. #. Check disk name:: ls -1 /dev/disk/by-id/ | grep -v '\-part[0-9]' #. Install GRUB to every disk:: for i in {target_disk2,target_disk3}; do grub-install /dev/disk/by-id/$i done Boot Environment Manager ~~~~~~~~~~~~~~~~~~~~~~~~ Optional: install `rozb3-pac `__ pacman hook and `bieaz `__ from AUR to create boot environments. Prebuilt packages are also available in the links above. Post installation ~~~~~~~~~~~~~~~~~ For post installation recommendations, see `ArchWiki `__. Remember to create separate datasets for individual users. Encrypt boot pool with LUKS --------------------------- If encryption is enabled earlier, boot pool can be optionally encrypted. This step will rebuild boot pool on a LUKS 1 container. Password must be entered interactively at GRUB and thus incompatible with `Supply password with SSH <#supply-password-with-ssh>`__. Encrypted boot pool protects initramfs from malicious modification and supports hibernation to encrypted swap. #. Create encryption keys:: mkdir /etc/cryptkey.d/ chmod 700 /etc/cryptkey.d/ dd bs=32 count=1 if=/dev/urandom of=/etc/cryptkey.d/lukskey-bpool_$INST_UUID dd bs=32 count=1 if=/dev/urandom of=/etc/cryptkey.d/zfskey-rpool_$INST_UUID #. Backup boot pool:: zfs snapshot -r bpool_$INST_UUID/sys@pre-luks zfs send -R bpool_$INST_UUID/sys@pre-luks > /root/bpool_$INST_UUID-pre-luks #. Check boot pool creation command:: zpool history bpool_$INST_UUID | head -n2 \ | grep 'zpool create' > /root/bpool_$INST_UUID-cmd Note the vdev disks at the end of the command. #. Unmount EFI partition:: umount /boot/efi umount /boot/efis/* # if backups exist #. Destroy boot pool:: zpool destroy bpool_$INST_UUID #. Enter LUKS password:: LUKS_PWD=rootpool #. Create LUKS containers:: for i in {disk1,disk2}; do cryptsetup luksFormat -q --type luks1 /dev/disk/by-id/$i-part2 --key-file /etc/cryptkey.d/lukskey-bpool_$INST_UUID echo $LUKS_PWD | cryptsetup luksAddKey /dev/disk/by-id/$i-part2 --key-file /etc/cryptkey.d/lukskey-bpool_$INST_UUID cryptsetup open /dev/disk/by-id/$i-part2 luks-bpool_$INST_UUID-$i-part2 --key-file /etc/cryptkey.d/lukskey-bpool_$INST_UUID echo luks-bpool_$INST_UUID-$i-part2 /dev/disk/by-id/$i-part2 /etc/cryptkey.d/lukskey-bpool_$INST_UUID discard >> /etc/crypttab done #. Embed key file in initramfs:: tee -a /etc/mkinitcpio.conf <> /etc/default/grub #. Install GRUB. See `GRUB Installation <#grub-installation>`__. #. Generate GRUB menu:: grub-mkconfig -o /boot/grub/grub.cfg #. **Important**: Back up root dataset key ``/etc/cryptkey.d/zfskey-rpool_$INST_UUID`` to a secure location. In the possible event of LUKS container corruption, data on root set will only be available with this key. Secure Boot ~~~~~~~~~~~ Recommended: With Secure Boot + encrypted boot pool + encrypted root dataset, a chain-of-trust can be established. #. Sign boot loader - Use boot loader signed by Microsoft Using a boot loader signed with Microsoft's key is the simplest and most direct approach to booting with Secure Boot active; however, it's also the most limiting approach. Use `shim-signed `__\ :sup:`AUR` and sign ``grubx64.efi`` with machine owner key. See `here `__. - Customized Secure Boot It's possible to replace Microsoft's keys with your own, which enables you to gain the benefits of Secure Boot without using either Shim. This can be a useful approach if you want the benefits of Secure Boot but don't want to trust Microsoft or any of the others who distribute binaries signed with Microsoft's keys. See `here `__. #. Set up a service to monitor and sign ``grubx64.efi``, as in `mirrored ESP <#mirror-efi-system-partition>`__. Hibernation ~~~~~~~~~~~ If a separate swap partition and `encrypted boot pool <#encrypt-boot-pool-with-LUKS>`__ have been configured, hibernation, also known as suspend-to-disk, can be enabled. #. Unload swap:: swapoff /dev/mapper/crypt-swap cryptsetup close crypt-swap #. Check partition name and remove crypttab entry:: grep crypt-swap /etc/crypttab | awk '{ print $2 }' # ${DISK}-part4 DISK=/dev/disk/by-id/nvme-foo # NO -part4 sed -i 's|crypt-swap.*||' /etc/crypttab Swap will be handled by ``encrypt`` initramfs hook. #. Create LUKS container:: dd bs=32 count=1 if=/dev/urandom of=/etc/cryptkey.d/lukskey-crypt-swap cryptsetup luksFormat -q --type luks2 ${DISK}-part4 --key-file /etc/cryptkey.d/lukskey-crypt-swap cryptsetup luksOpen ${DISK}-part4 crypt-swap --key-file /etc/cryptkey.d/lukskey-crypt-swap --allow-discards mkswap /dev/mapper/crypt-swap swapon /dev/mapper/crypt-swap #. Configure mkinitcpio:: sed -i 's|FILES=(|FILES=(/etc/cryptkey.d/lukskey-crypt-swap |' /etc/mkinitcpio.conf sed -i 's| zfs | encrypt resume zfs |' /etc/mkinitcpio.conf #. Add kernel command line:: echo "GRUB_CMDLINE_LINUX=\"cryptdevice=PARTUUID=$(blkid -s PARTUUID -o value ${DISK}-part4):crypt-swap:allow-discards \ cryptkey=rootfs:/etc/cryptkey.d/lukskey-crypt-swap \ resume=/dev/mapper/crypt-swap\"" >> /etc/default/grub #. Regenerate initramfs and GRUB menu:: mkinitcpio -P grub-mkconfig -o /boot/grub/grub.cfg #. Test hibernation:: systemctl hibernate Close all program before testing, just in case. If hibernation works, your computer will shut down. Power it on. Computer should return to the previous state seamlessly. Enter LUKS password in GRUB rescue ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Using LUKS encryption for boot pool, if the password entered is wrong, GRUB will drop to ``grub-rescue``:: Attempting to decrypt master key... Enter passphrase for hd0,gpt2 (c0987ea1a51049e9b3056622804de62a): error: access denied. error: no such cryptodisk found. Entering rescue mode... grub rescue> Try entering the password again with:: grub rescue> cryptomount hd0,gpt2 Attempting to decrypt master key... Enter passphrase for hd0,gpt2 (c0987ea1a51049e9b3056622804de62a): Slot 1 opened grub rescue> insmod normal grub rescue> normal GRUB should then boot normally. Change GRUB prefix when disk fails ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Using encryption, when disk failed, GRUB might fail to boot. .. code-block:: text Welcome to GRUB! error: no such cryptodisk found. Attempting to decrypt master key... Enter passphrase for hd0,gpt2 (c0987ea1a51049e9b3056622804de62a): Slot 1 opened error: disk `cryptouuid/47ed1b7eb0014bc9a70aede3d8714faf' not found. Entering rescue mode... grub rescue> Ensure ``Slot 1 opened`` message is shown. If ``error: access denied.`` is shown, the password entered is wrong. #. Check prefix:: grub rescue > set # prefix=(cryptouuid/47ed1b7eb0014bc9a70aede3d8714faf)/sys/BOOT/default@/grub # root=cryptouuid/47ed1b7eb0014bc9a70aede3d8714faf #. Replace ``cryptouuid/UUID`` with ``crypto0``:: grub rescue> prefix=(crypto0)/sys/BOOT/default@/grub grub rescue> root=crypto0 #. Boot GRUB:: grub rescue> insmod normal grub rescue> normal GRUB should then boot normally. After entering system, promote one backup to ``/boot/efi`` and reinstall GRUB with ``grub-install``. Recovery -------- Load grub.cfg in GRUB command line ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. Press ``c`` at GRUB menu. #. Check prefix:: grub > set # ... # unencrypted bpool # prefix=(hd0,gpt2)/sys/BOOT/default@/grub # encrypted bpool # prefix=(cryptouuid/UUID)/sys/BOOT/default@/grub #. List available boot environments:: # unencrypted bpool grub > ls (hd0,gpt2)/sys/BOOT # press tab after 'T' # encrypted bpool grub > ls (crypto0)/sys/BOOT # press tab after 'T' Possible files are: @/ default/ pac-multm2/ #. Set new prefix:: # unencrypted bpool grub > prefix=(hd0,gpt2)/sys/BOOT/pac-multm2@/grub # encrypted bpool grub > prefix=(crypto0)/sys/BOOT/pac-multm2@/grub #. Load config from new prefix:: grub > normal New entries are shown below the old ones. Rescue in Live Environment ~~~~~~~~~~~~~~~~~~~~~~~~~~~ #. `Download Arch Linux live image <#download-arch-linux-live-image>`__. #. `Prepare the Live Environment <#prepare-the-live-environment>`__. #. Check the ``INST_UUID`` with ``zpool import``. #. Set variables:: INST_MNT=$(mktemp -d) INST_UUID=abc123 #. Import and unlock root and boot pool:: zpool import -N -R $INST_MNT rpool_$INST_UUID zpool import -N -R $INST_MNT bpool_$INST_UUID If using password:: zfs load-key rpool_$INST_UUID/sys If using keyfile:: zfs load-key -L file:///path/to/keyfile rpool_$INST_UUID/sys #. Find the current boot environment:: zfs list BE=default #. Mount root filesystem:: zfs mount rpool_$INST_UUID/sys/ROOT/$BE #. chroot into the system:: arch-chroot $INST_MNT /bin/bash --login mount /boot mount /boot/efi zfs mount -a #. Finish rescue:: exit umount $INST_MNT/boot/efi zpool export bpool_$INST_UUID zpool export rpool_$INST_UUID reboot