A/B Dual-Root na Arch Linux — Odporność na Awarie Zasilania

# Synchronizacja home na dysk zewnętrzny
rsync -aAXH --delete --info=progress2 /home/ /mnt/backup/home-backup/

# Weryfikacja
du -sh /mnt/backup/home-backup/
ls -la /mnt/backup/home-backup/

# Sprawdzenie rzeczywistych rozmiarów LV przed resize
sudo lvs --units g vg0

# Otwieramy LUKS i aktywujemy VG
cryptsetup open /dev/nvme0n1p2 cryptroot
vgchange -ay

# Zmniejszamy root: 105G → 65G
e2fsck -f /dev/vg0/root
resize2fs /dev/vg0/root 60G        # fs mniejszy niż LV
lvreduce -L 65G /dev/vg0/root
resize2fs /dev/vg0/root            # rozciągamy fs do końca LV
e2fsck -f /dev/vg0/root

# Zmniejszamy home: 331G → 284G
e2fsck -f /dev/vg0/home
resize2fs /dev/vg0/home 279G
lvreduce -L 284G /dev/vg0/home
resize2fs /dev/vg0/home
e2fsck -f /dev/vg0/home

# Tworzymy root-backup
lvcreate -L 65G -n root-backup vg0
mkfs.ext4 -L root-backup /dev/vg0/root-backup

# Pierwszy sync root → root-backup
mkdir -p /mnt/root /mnt/root-backup
mount /dev/vg0/root /mnt/root
mount /dev/vg0/root-backup /mnt/root-backup
rsync -aAXH --delete --info=progress2 \
  --exclude=/proc --exclude=/sys --exclude=/dev --exclude=/run \
  --exclude=/tmp --exclude=/boot --exclude=/home \
  --exclude=/mnt --exclude=/lost+found \
  /mnt/root/ /mnt/root-backup/

# Aktualizacja fstab w backupie
ROOT_UUID=$(blkid -s UUID -o value /dev/vg0/root)
BACKUP_UUID=$(blkid -s UUID -o value /dev/vg0/root-backup)
sed -i "s/$ROOT_UUID/$BACKUP_UUID/" /mnt/root-backup/etc/fstab

# Zamknięcie i restart
umount /mnt/root /mnt/root-backup
vgchange -an vg0
cryptsetup close cryptroot
reboot

#!/usr/bin/env bash
set -euo pipefail

DIR=/var/lib/sync-root-backup
FLAG="$DIR/pending"

mkdir -p "$DIR"
chmod 755 "$DIR"
date '+%Y-%m-%d %H:%M:%S' > "$FLAG"
chmod 644 "$FLAG"

#!/usr/bin/env bash
set -euo pipefail

BACKUP_DEV=/dev/vg0/root-backup
MOUNT_POINT=/mnt/root-backup
FLAG=/var/lib/sync-root-backup/pending
LOG_TAG=sync-root-backup

log() { logger -t "$LOG_TAG" "$*"; echo "$*"; }

if [[ ! -b "$BACKUP_DEV" ]]; then
    log "Błąd: $BACKUP_DEV nie istnieje. Czy wykonano resize LVM?"
    exit 1
fi

if mountpoint -q "$MOUNT_POINT"; then
    log "Błąd: $MOUNT_POINT jest już podmontowany."
    exit 1
fi

mkdir -p "$MOUNT_POINT"
mount "$BACKUP_DEV" "$MOUNT_POINT"
log "Zamontowano $BACKUP_DEV na $MOUNT_POINT"

START=$(date +%s)

rsync -aAXH --delete \
    --exclude=/proc \
    --exclude=/sys \
    --exclude=/dev \
    --exclude=/run \
    --exclude=/tmp \
    --exclude=/boot \
    --exclude=/home \
    --exclude=/mnt \
    --exclude=/lost+found \
    --exclude=/var/lib/sync-root-backup \
    --info=progress2 \
    / "$MOUNT_POINT"/

ROOT_UUID=$(blkid -s UUID -o value /dev/vg0/root)
BACKUP_UUID=$(blkid -s UUID -o value "$BACKUP_DEV")
sed -i "s/$ROOT_UUID/$BACKUP_UUID/" "$MOUNT_POINT/etc/fstab"
log "Zaktualizowano fstab: $ROOT_UUID → $BACKUP_UUID"

rm -f "$FLAG"
umount "$MOUNT_POINT"

ELAPSED=$(( $(date +%s) - START ))
log "Sync zakończony w ${ELAPSED}s."

#!/usr/bin/env bash
set -euo pipefail

ROOT_DEV=/dev/vg0/root
BACKUP_DEV=/dev/vg0/root-backup
MOUNT_POINT=/mnt/root-restore
FLAG=/var/lib/sync-root-backup/pending
LOG_TAG=restore-root

log() { logger -t "$LOG_TAG" "$*"; echo "$*"; }

LIVE_DEV=$(findmnt -n -o SOURCE /)
if [[ "$LIVE_DEV" != "$BACKUP_DEV" ]]; then
    log "Błąd: Nie uruchomiono z partycji root-backup (aktywna: $LIVE_DEV)."
    log "Ten skrypt uruchamiaj wyłącznie po zabootowaniu z 'Arch Linux (backup)'."
    exit 1
fi

if [[ ! -b "$ROOT_DEV" ]]; then
    log "Błąd: $ROOT_DEV nie istnieje."
    exit 1
fi

if mountpoint -q "$MOUNT_POINT"; then
    log "Błąd: $MOUNT_POINT jest już podmontowany."
    exit 1
fi

mkdir -p "$MOUNT_POINT"
mount "$ROOT_DEV" "$MOUNT_POINT"
log "Zamontowano $ROOT_DEV na $MOUNT_POINT"

START=$(date +%s)

rsync -aAXH --delete \
    --exclude=/proc \
    --exclude=/sys \
    --exclude=/dev \
    --exclude=/run \
    --exclude=/tmp \
    --exclude=/boot \
    --exclude=/home \
    --exclude=/mnt \
    --exclude=/lost+found \
    --exclude=/var/lib/sync-root-backup \
    --info=progress2 \
    / "$MOUNT_POINT"/

BACKUP_UUID=$(blkid -s UUID -o value "$BACKUP_DEV")
ROOT_UUID=$(blkid -s UUID -o value "$ROOT_DEV")
sed -i "s/$BACKUP_UUID/$ROOT_UUID/" "$MOUNT_POINT/etc/fstab"
log "Zaktualizowano fstab: $BACKUP_UUID → $ROOT_UUID"

rm -f "$MOUNT_POINT$FLAG"

umount "$MOUNT_POINT"

ELAPSED=$(( $(date +%s) - START ))
log "Przywracanie zakończone w ${ELAPSED}s. Uruchom ponownie i zabootuj z 'Arch Linux'."

[Trigger]
Operation = Install
Operation = Upgrade
Operation = Remove
Type = Package
Target = *

[Action]
Description = Oznaczanie backupu root jako nieaktualny...
When = PostTransaction
Exec = /usr/local/bin/mark-root-backup-pending

# A/B root backup reminder
_sync_root_check() {
  local live_dev
  live_dev=$(findmnt -n -o SOURCE / 2>/dev/null)
  if [[ "$live_dev" == "/dev/vg0/root-backup" ]]; then
    echo "[!] Uruchomiono z partycji root-backup. Uruchom: sudo restore-root-from-backup"
    return
  fi
  local flag="/var/lib/sync-root-backup/pending"
  [[ -f "$flag" ]] || return
  local ts
  ts=$(cat "$flag")
  echo "[!] Backup root niezsynchronizowany od $ts. Uruchom: sudo sync-root-backup"
}
_sync_root_check

title   Arch Linux (backup)
linux   /vmlinuz-linux
initrd  /intel-ucode.img
initrd  /initramfs-linux.img
options rd.luks.name=f2898094-ad76-47cc-a637-61d629a01021=cryptroot \
        root=/dev/vg0/root-backup rw \
        resume=UUID=fb45ad19-0717-4259-bf82-ab132e2c031b \
        rw quiet splash loglevel=3 \
        modprobe.blacklist=nouveau nouveau.modeset=0