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diff --git a/docs/research-sandreas-zarch.org b/docs/research-sandreas-zarch.org deleted file mode 100644 index 55bc77b..0000000 --- a/docs/research-sandreas-zarch.org +++ /dev/null @@ -1,365 +0,0 @@ -#+TITLE: Research: sandreas/zarch ZFSBootMenu Installation -#+DATE: 2026-01-22 -#+AUTHOR: Research Notes - -* Overview - -This document summarizes research on the [[https://github.com/sandreas/zarch][sandreas/zarch]] GitHub repository for -Arch Linux ZFS installation. The project uses ZFSBootMenu, native encryption, -and automatic snapshots via zrepl. - -* Project Philosophy - -sandreas/zarch is described as a "single, non-modular file with some minor -config profiles" - the author explicitly avoids a "modular multi-script beast." -This contrasts with our more modular approach but offers useful patterns. - -** Key Features -- ZFSBootMenu as bootloader (not GRUB) -- Native ZFS encryption (AES-256-GCM) -- Automatic snapshots via zrepl -- EFI-only (no BIOS support) -- Profile-based configuration - -* ZFSBootMenu Installation - -** Download and Install -#+begin_src bash -# Create EFI directory -mkdir -p /efi/EFI/ZBM - -# Download latest ZFSBootMenu EFI binary -wget -c https://get.zfsbootmenu.org/latest.EFI -O /efi/EFI/ZBM/ZFSBOOTMENU.EFI - -# Or use curl variant -curl -o /boot/efi/EFI/ZBM/VMLINUZ.EFI -L https://get.zfsbootmenu.org/efi -#+end_src - -** EFI Boot Entry Registration -#+begin_src bash -efibootmgr --disk $DISK --part 1 \ - --create \ - --label "ZFSBootMenu" \ - --loader '\EFI\ZBM\ZFSBOOTMENU.EFI' \ - --unicode "spl_hostid=$(hostid) zbm.timeout=3 zbm.prefer=zroot zbm.import_policy=hostid" \ - --verbose -#+end_src - -** Key ZFSBootMenu Parameters -| Parameter | Purpose | -|------------------------+------------------------------------------------| -| zbm.timeout=N | Seconds to wait before auto-booting default | -| zbm.prefer=POOL | Preferred pool for default boot environment | -| zbm.import_policy | Pool import strategy (hostid recommended) | -| zbm.skip | Skip menu and boot default immediately | -| zbm.show | Force menu display | -| spl_hostid=0xXXXXXXXX | Host ID for pool import validation | - -** Kernel Command Line for Boot Environments -#+begin_src bash -# Set inherited command line on ROOT dataset -zfs set org.zfsbootmenu:commandline="quiet loglevel=0" zroot/ROOT - -# Set pool bootfs property -zpool set bootfs=zroot/ROOT/arch zroot -#+end_src - -* Dataset Layout - -** zarch Dataset Structure -#+begin_example -$POOL mountpoint=none -$POOL/ROOT mountpoint=none (container for boot environments) -$POOL/ROOT/arch mountpoint=/, canmount=noauto (active root) -$POOL/home mountpoint=/home (shared across boot environments) -#+end_example - -** Comparison: Our archzfs Dataset Structure -#+begin_example -zroot mountpoint=none, canmount=off -zroot/ROOT mountpoint=none, canmount=off -zroot/ROOT/default mountpoint=/, canmount=noauto, reservation=5-20G -zroot/home mountpoint=/home -zroot/home/root mountpoint=/root -zroot/media mountpoint=/media, compression=off -zroot/vms mountpoint=/vms, recordsize=64K -zroot/var mountpoint=/var, canmount=off -zroot/var/log mountpoint=/var/log -zroot/var/cache mountpoint=/var/cache -zroot/var/lib mountpoint=/var/lib, canmount=off -zroot/var/lib/pacman mountpoint=/var/lib/pacman -zroot/var/lib/docker mountpoint=/var/lib/docker -zroot/var/tmp mountpoint=/var/tmp, auto-snapshot=false -zroot/tmp mountpoint=/tmp, auto-snapshot=false -#+end_example - -** Key Differences -- zarch: Minimal dataset layout (ROOT, home) -- archzfs: Fine-grained datasets with workload-specific tuning -- archzfs: Separate /var/log, /var/cache, /var/lib/docker -- archzfs: recordsize=64K for VM storage -- archzfs: compression=off for media (already compressed) - -* ZFS Pool Creation - -** zarch Pool Creation (with encryption) -#+begin_src bash -zpool create -f \ - -o ashift=12 \ - -O compression=lz4 \ - -O acltype=posixacl \ - -O xattr=sa \ - -O relatime=off \ - -O atime=off \ - -O encryption=aes-256-gcm \ - -O keylocation=prompt \ - -O keyformat=passphrase \ - -o autotrim=on \ - -m none \ - $POOL ${DISK}-part2 -#+end_src - -** Our archzfs Pool Creation (with encryption) -#+begin_src bash -zpool create -f \ - -o ashift="$ASHIFT" \ - -o autotrim=on \ - -O acltype=posixacl \ - -O atime=off \ - -O canmount=off \ - -O compression="$COMPRESSION" \ - -O dnodesize=auto \ - -O normalization=formD \ - -O relatime=on \ - -O xattr=sa \ - -O encryption=aes-256-gcm \ - -O keyformat=passphrase \ - -O keylocation=prompt \ - -O mountpoint=none \ - -R /mnt \ - "$POOL_NAME" $pool_config -#+end_src - -** Key Differences -| Option | zarch | archzfs | Notes | -|-----------------+-------------------+-----------------------+---------------------------------| -| compression | lz4 | zstd (configurable) | zstd better ratio, more CPU | -| atime | off | off | Same | -| relatime | off | on | archzfs uses relatime instead | -| dnodesize | (default) | auto | Better extended attribute perf | -| normalization | (default) | formD | Unicode consistency | - -* Snapshot Automation - -** zarch: zrepl Configuration - -zarch uses zrepl for automated snapshots with this retention grid: - -#+begin_example -1x1h(keep=4) | 24x1h(keep=1) | 7x1d(keep=1) | 4x1w(keep=1) | 12x4w(keep=1) | 1x53w(keep=1) -#+end_example - -This means: -- Keep 4 snapshots within the last hour -- Keep 1 snapshot per hour for 24 hours -- Keep 1 snapshot per day for 7 days -- Keep 1 snapshot per week for 4 weeks -- Keep 1 snapshot per 4 weeks for 12 periods (48 weeks) -- Keep 1 snapshot per year - -#+begin_src yaml -# Example zrepl.yml structure -jobs: - - name: snapjob - type: snap - filesystems: - "zroot<": true - snapshotting: - type: periodic - interval: 15m - prefix: zrepl_ - pruning: - keep: - - type: grid - grid: 1x1h(keep=all) | 24x1h | 14x1d - regex: "^zrepl_.*" - - type: regex - negate: true - regex: "^zrepl_.*" -#+end_src - -** archzfs: Pacman Hook Approach - -Our approach uses pre-transaction snapshots: -#+begin_src bash -# /etc/pacman.d/hooks/zfs-snapshot.hook -[Trigger] -Operation = Upgrade -Operation = Install -Operation = Remove -Type = Package -Target = * - -[Action] -Description = Creating ZFS snapshot before pacman transaction... -When = PreTransaction -Exec = /usr/local/bin/zfs-pre-snapshot -#+end_src - -** Comparison: Snapshot Approaches -| Feature | zrepl (zarch) | Pacman Hook (archzfs) | -|-------------------+--------------------------+------------------------------| -| Trigger | Time-based (15 min) | Event-based (pacman) | -| Retention | Complex grid policy | Manual or sanoid | -| Granularity | High (frequent) | Package transaction focused | -| Recovery Point | ~15 minutes | Last package operation | -| Storage overhead | Higher (more snapshots) | Lower (fewer snapshots) | - -** Alternative: sanoid (mentioned in archzfs) -Sanoid provides similar functionality to zrepl with simpler configuration: -#+begin_src ini -# /etc/sanoid/sanoid.conf -[zroot/ROOT/default] -use_template = production -recursive = yes - -[template_production] -frequently = 0 -hourly = 24 -daily = 7 -weekly = 4 -monthly = 12 -yearly = 1 -autosnap = yes -autoprune = yes -#+end_src - -* EFI and Boot Partition Strategy - -** zarch: 512MB EFI, ZFSBootMenu -- Single 512MB EFI partition (type EF00) -- ZFSBootMenu EFI binary downloaded from upstream -- No GRUB, no separate boot partition on ZFS -- Kernel/initramfs stored on ZFS root (ZFSBootMenu reads them) - -** archzfs: 1GB EFI, GRUB with ZFS Support -- 1GB EFI partition per disk -- GRUB with ZFS module for pool access -- Redundant EFI partitions synced via rsync -- Boot files in EFI partition (not ZFS) - -** Trade-offs - -| Aspect | ZFSBootMenu | GRUB + ZFS | -|---------------------+--------------------------------+------------------------------| -| Boot environment | Native (designed for ZFS) | Requires ZFS module | -| Snapshot booting | Built-in, interactive | Custom GRUB menu entries | -| Encryption | Prompts for key automatically | More complex setup | -| EFI space needed | Minimal (~512MB) | Larger (kernel/initramfs) | -| Complexity | Simpler (single binary) | More moving parts | -| Recovery | Can browse/rollback at boot | Requires grub.cfg regen | - -* Pacman Hooks and Systemd Services - -** zarch Services -#+begin_example -zfs-import-cache -zfs-import.target -zfs-mount -zfs-zed -zfs.target -set-locale-once.service (custom first-boot locale config) -#+end_example - -** archzfs Services -#+begin_example -zfs.target -zfs-import-scan.service (instead of cache-based) -zfs-mount.service -zfs-import.target -NetworkManager -avahi-daemon -sshd -#+end_example - -** Key Difference: Import Method -- zarch: Uses zfs-import-cache (requires cachefile) -- archzfs: Uses zfs-import-scan (scans with blkid, no cachefile needed) - -The scan method is simpler and more portable (works if moving disks between -systems). - -* mkinitcpio Configuration - -** zarch Approach -#+begin_src bash -sed -i '/^HOOKS=/s/block filesystems/block zfs filesystems/g' /etc/mkinitcpio.conf -#+end_src - -** archzfs Approach -#+begin_src bash -HOOKS=(base udev microcode modconf kms keyboard keymap consolefont block zfs filesystems) -#+end_src - -** Important Notes -- Both use busybox-based udev (not systemd hook) -- archzfs explicitly removes autodetect to ensure all storage drivers included -- archzfs removes fsck (ZFS doesn't use it) -- archzfs includes microcode early loading - -* Useful Patterns to Consider - -** 1. Profile-Based Configuration -zarch uses a profile directory system: -#+begin_example -default/ - archpkg.txt # Official packages - aurpkg.txt # AUR packages - services.txt # Services to enable - zarch.conf # Core configuration - custom-chroot.sh # Custom post-install -#+end_example - -This allows maintaining multiple configurations (desktop, server, VM) cleanly. - -** 2. ZFSBootMenu for Simpler Boot -For future consideration: -- Native ZFS boot environment support -- Interactive snapshot selection at boot -- Simpler encryption key handling -- Smaller EFI partition needs - -** 3. zrepl for Time-Based Snapshots -For systems needing frequent snapshots beyond pacman transactions: -- 15-minute intervals for development machines -- Complex retention policies -- Replication to remote systems - -** 4. AUR Helper Installation Pattern -#+begin_src bash -# Build yay as regular user, install as root -su -c "git clone https://aur.archlinux.org/yay-bin.git" "$USER_NAME" -arch-chroot -u "$USER_NAME" /mnt makepkg -D /home/$USER_NAME/yay-bin -s -pacman -U --noconfirm yay-bin-*.pkg.tar.* -#+end_src - -* References - -- [[https://github.com/sandreas/zarch][sandreas/zarch GitHub Repository]] -- [[https://zfsbootmenu.org/][ZFSBootMenu Official Site]] -- [[https://docs.zfsbootmenu.org/en/latest/][ZFSBootMenu Documentation]] -- [[https://zrepl.github.io/][zrepl Documentation]] -- [[https://wiki.archlinux.org/title/ZFS][Arch Wiki: ZFS]] -- [[https://github.com/acrion/zfs-autosnap][zfs-autosnap - Pre-upgrade Snapshots]] -- [[https://aur.archlinux.org/packages/pacman-zfs-hook][pacman-zfs-hook AUR Package]] -- [[https://florianesser.ch/posts/20220714-arch-install-zbm/][Guide: Install Arch Linux on encrypted zpool with ZFSBootMenu]] - -* Action Items for archzfs - -Based on this research, potential improvements: - -1. [ ] Consider adding ZFSBootMenu as alternative bootloader option -2. [ ] Evaluate zrepl for systems needing frequent time-based snapshots -3. [ ] Document the grub-zfs-snap vs ZFSBootMenu trade-offs -4. [ ] Consider profile-based configuration for different use cases -5. [ ] Add sanoid configuration to archsetup for automated snapshot retention |