Can`t find /boot/zfs/loader

12sunflowers
Ah, I see. Your ZFS pool was likely destroyed by this command: 155 sudo zpool create zroot sdb2 -f

The -f flag forcibly overwrites existing ZFS metadata. Any prior pool on sdb2 was wiped at that point.

The zpool import error about com.klarasystems:vdev_zaps_v2 confirms GhostBSD upgraded the pool to OpenZFS 2.2, which Devuan (OpenZFS 2.1) cannot read — but this mismatch did not cause the data loss.

The data loss was caused by using zpool create on a disk that still held a valid pool.

Here's a script that performs all recovery-safe steps using zdb and zpool import. It captures output, avoids any writes by default, and tells you what to do next.

#!/bin/bash
# zfs-recover-check.sh – Safely analyze and check recoverability of a damaged ZFS pool

set -euo pipefail

POOL="zroot"
DISK="/dev/sdb2"  # Adjust if your overwritten device is different
OUTDIR="./zfs_recovery_$(date +%Y%m%d_%H%M%S)"
mkdir -p "$OUTDIR"

echo "[*] Step 1: Running zdb to scan pool metadata (non-destructive)..."
zdb -e -bcsvL "$POOL" > "$OUTDIR/zdb-output.txt" 2>&1 || echo "[!] zdb failed (check $OUTDIR/zdb-output.txt)"

echo "[*] Step 2: Attempting dry-run rollback import (read-only)..."
zpool import -F -n -o readonly=on "$POOL" > "$OUTDIR/zpool-dryrun.txt" 2>&1 || echo "[!] zpool import dry-run failed (check $OUTDIR/zpool-dryrun.txt)"

echo
echo "=== SUMMARY ==="
echo "Output saved to: $OUTDIR"
echo
echo "• Review zdb output:        less $OUTDIR/zdb-output.txt"
echo "• Review rollback preview:  less $OUTDIR/zpool-dryrun.txt"
echo
echo "If rollback looks safe, you can try:"
echo "  sudo zpool import -F -o readonly=on $POOL"
echo
echo "Then list datasets with:"
echo "  sudo zfs list -r $POOL"

Here is an updated version of the script.

#!/bin/bash
# zfs-recover-check.sh – Safely analyze and check recoverability of a damaged ZFS pool

set -euo pipefail

# === USER CONFIGURABLE ===
POOL="zroot"
DEVICE_HINT="/dev"  # Change to /dev/disk/by-id or other path if needed
# ==========================

TIMESTAMP=$(date +%Y%m%d_%H%M%S)
OUTDIR="./zfs_recovery_$TIMESTAMP"
mkdir -p "$OUTDIR"

log()     { echo "[*] $1"; }
warn()    { echo "[!] $1" >&2; }
fail_exit() { warn "$1"; exit 1; }

command -v zdb >/dev/null 2>&1 || fail_exit "zdb not found. Please install OpenZFS utilities."
command -v zpool >/dev/null 2>&1 || fail_exit "zpool not found. Please install OpenZFS utilities."

log "Step 1: Attempting to locate pool '$POOL'..."
if ! zpool import | grep -q "$POOL"; then
  warn "Pool '$POOL' not found in system import list."
  log "Attempting to scan pool by device path: $DEVICE_HINT..."
  if ! zpool import -d "$DEVICE_HINT" | grep -q "$POOL"; then
    warn "Pool still not found via 'zpool import -d $DEVICE_HINT'. Trying anyway..."
  else
    log "Pool '$POOL' found via device scan."
  fi
else
  log "Pool '$POOL' is visible to zpool import."
fi

log "Step 2: Running zdb to analyze pool metadata (non-destructive)..."
if ! zdb -e -bcsvL "$POOL" > "$OUTDIR/zdb-output.txt" 2>&1; then
  warn "zdb failed. Metadata may be corrupt. See: $OUTDIR/zdb-output.txt"
else
  log "zdb scan complete. Output: $OUTDIR/zdb-output.txt"
fi

log "Step 3: Attempting dry-run rollback import (read-only)..."
if ! zpool import -F -n -o readonly=on -d "$DEVICE_HINT" "$POOL" > "$OUTDIR/zpool-dryrun.txt" 2>&1; then
  warn "Dry-run rollback failed. Review: $OUTDIR/zpool-dryrun.txt"
else
  log "Dry-run rollback complete. Output: $OUTDIR/zpool-dryrun.txt"
fi

echo
echo "=== SUMMARY ==="
echo "Output directory: $OUTDIR"
echo
echo "• zdb output:       less $OUTDIR/zdb-output.txt"
echo "• rollback preview: less $OUTDIR/zpool-dryrun.txt"
echo
echo "To attempt actual import:"
echo "  sudo zpool import -F -o readonly=on -d $DEVICE_HINT $POOL"
echo
echo "Then list datasets:"
echo "  sudo zfs list -r $POOL"

12sunflowers
Here is an updated script.

#!/bin/bash
# zfs-recovery-toolkit.sh – ZFS recovery script with detailed logs and structured report

set -euo pipefail

# === USER CONFIGURABLE ===
POOL="${1:-zroot}"
DEVICE_HINT="${2:-/dev}"
AUTO_IMPORT="yes"
AUTO_EXPORT="yes"
# ==========================

TIMESTAMP=$(date +%Y%m%d_%H%M%S)
HOST=$(hostname)
OUTDIR="./zfs_recovery_${POOL}_${TIMESTAMP}"
REPORT="$OUTDIR/recovery-report.txt"
mkdir -p "$OUTDIR"

log()     { echo "[*] $(date +%H:%M:%S) $1"; echo "[*] $1" >> "$REPORT"; }
warn()    { echo "[!] $(date +%H:%M:%S) $1" >&2; echo "[!] $1" >> "$REPORT"; }
error()   { echo "[✘] $(date +%H:%M:%S) $1" >&2; echo "[ERROR] $1" >> "$REPORT"; }
fail_exit() { error "$1"; echo "[ABORTED]" >> "$REPORT"; exit 1; }

# === BEGIN REPORT ===
{
echo "ZFS Recovery Report"
echo "==================="
echo "Host: $HOST"
echo "Time: $(date)"
echo "Pool: $POOL"
echo "Device Hint: $DEVICE_HINT"
echo "Output Dir: $OUTDIR"
echo
} > "$REPORT"

# --- Check for required commands ---
for cmd in zdb zpool zfs; do
  if ! command -v "$cmd" >/dev/null 2>&1; then
    fail_exit "Required command '$cmd' not found in PATH."
  fi
done

log "Step 1: Checking pool visibility..."
if ! zpool import 2> "$OUTDIR/import-visible-error.txt" | grep -q "$POOL"; then
  warn "Pool not found in normal import list. Trying device hint scan..."
  if ! zpool import -d "$DEVICE_HINT" > "$OUTDIR/import-scan.txt" 2> "$OUTDIR/import-scan-error.txt"; then
    warn "Device scan failed. See $OUTDIR/import-scan-error.txt"
  fi
  if grep -q "$POOL" "$OUTDIR/import-scan.txt"; then
    log "Pool '$POOL' found via device hint."
  else
    warn "Pool '$POOL' still not found. Continuing with caution."
  fi
else
  log "Pool '$POOL' is visible via normal import."
fi

log "Step 2: Analyzing pool metadata with zdb..."
if ! zdb -e -bcsvL "$POOL" > "$OUTDIR/zdb-output.txt" 2> "$OUTDIR/zdb-error.txt"; then
  warn "zdb failed. Output saved to $OUTDIR/zdb-error.txt"
else
  log "zdb completed successfully. Output: $OUTDIR/zdb-output.txt"
fi

log "Step 3: Attempting dry-run import with rollback enabled..."
if ! zpool import -F -n -o readonly=on -d "$DEVICE_HINT" "$POOL" > "$OUTDIR/zpool-dryrun.txt" 2> "$OUTDIR/zpool-dryrun-error.txt"; then
  warn "Dry-run import failed. See $OUTDIR/zpool-dryrun-error.txt"
else
  log "Dry-run import succeeded. See $OUTDIR/zpool-dryrun.txt"
fi

if [[ "$AUTO_IMPORT" == "yes" ]]; then
  if zpool list | grep -q "^$POOL"; then
    log "Pool '$POOL' already imported. Skipping read-only import."
  else
    log "Step 4: Performing safe read-only import..."
    if ! zpool import -F -o readonly=on -d "$DEVICE_HINT" "$POOL" > "$OUTDIR/zpool-import.txt" 2> "$OUTDIR/zpool-import-error.txt"; then
      warn "Read-only import failed. See $OUTDIR/zpool-import-error.txt"
    else
      log "Read-only import succeeded. See $OUTDIR/zpool-import.txt"
    fi
  fi

  log "Step 5: Listing datasets..."
  if ! zfs list -r "$POOL" > "$OUTDIR/zfs-list.txt" 2> "$OUTDIR/zfs-list-error.txt"; then
    warn "Dataset listing failed. See $OUTDIR/zfs-list-error.txt"
  else
    log "Datasets listed successfully. See $OUTDIR/zfs-list.txt"
  fi

  if [[ "$AUTO_EXPORT" == "yes" ]]; then
    log "Step 6: Exporting the pool..."
    if ! zpool export "$POOL" > "$OUTDIR/zpool-export.txt" 2> "$OUTDIR/zpool-export-error.txt"; then
      warn "Export failed. See $OUTDIR/zpool-export-error.txt"
    else
      log "Export completed successfully. See $OUTDIR/zpool-export.txt"
    fi
  else
    log "AUTO_EXPORT disabled. Pool remains imported (read-only)."
  fi
else
  log "AUTO_IMPORT disabled. No pool was imported."
fi

# --- Final Summary ---
{
echo
echo "Final Notes:"
echo "  - All operations were performed in non-destructive read-only mode."
echo "  - No datasets were mounted."
echo "  - Log and output directory: $OUTDIR"
echo "[COMPLETED]"
} >> "$REPORT"

log "Recovery script completed. Review $REPORT for details."

12sunflowers
Here is an updated script that safely inspects and optionally imports a ZFS pool in a read-only, non-destructive manner. It is designed to assist in data recovery when a pool appears damaged, was not cleanly exported, or is being accessed from a different system.

#!/bin/bash
# zfs-recovery-toolkit.sh – ZFS recovery script with detailed logs and structured report

set -euo pipefail

# === USER CONFIGURABLE ===
POOL="${1:-zroot}"
DEVICE_HINT="${2:-/dev}"
DEBUG="${3:-no}"
AUTO_IMPORT="yes"
AUTO_EXPORT="yes"
# ==========================

# --- Check for required commands early ---
for cmd in zdb zpool zfs; do
  command -v "$cmd" >/dev/null 2>&1 || {
    echo "[✘] Required command '$cmd' not found in PATH." >&2; exit 1;
  }
done

[[ -z "$POOL" ]] && { echo "[✘] POOL name must not be empty." >&2; exit 1; }
[[ ! -d "$DEVICE_HINT" ]] && { echo "[✘] DEVICE_HINT '$DEVICE_HINT' is not a valid directory." >&2; exit 1; }

[[ "$DEBUG" == "yes" ]] && set -x

TIMESTAMP=$(date +%Y%m%d_%H%M%S)
HOST=$(hostname)
OUTDIR="./zfs_recovery_${POOL}_${TIMESTAMP}"
REPORT="$OUTDIR/recovery-report.txt"
mkdir -p "$OUTDIR"

log()     { echo "[*] $(date +%H:%M:%S) $1"; echo "[*] $1" >> "$REPORT"; }
warn()    { echo "[!] $(date +%H:%M:%S) $1" >&2; echo "[!] $1" >> "$REPORT"; }
error()   { echo "[✘] $(date +%H:%M:%S) $1" >&2; echo "[ERROR] $1" >> "$REPORT"; }
fail_exit() { error "$1"; echo "[ABORTED]" >> "$REPORT"; exit 1; }

trap 'echo "[!] Script interrupted or failed unexpectedly." >> "$REPORT"' EXIT

# === DISCLAIMER ===
echo "WARNING: This tool performs low-level read-only inspection of ZFS pools." >&2
echo "It attempts recovery in a non-destructive manner, but improper use may risk data loss." >&2
echo "Ensure you have backups. Continue at your own risk." >&2
read -rp "Do you wish to continue? (yes/no): " CONFIRM
if [[ "$CONFIRM" != "yes" ]]; then
  fail_exit "User aborted script."
fi

# === BEGIN REPORT ===
{
echo "ZFS Recovery Report"
echo "==================="
echo "Host: $HOST"
echo "Time: $(date)"
echo "Pool: $POOL"
echo "Device Hint: $DEVICE_HINT"
echo "Output Dir: $OUTDIR"
echo
echo "Disclaimer acknowledged: user chose to proceed."
} > "$REPORT"

log "Step 1: Checking pool visibility..."
if ! zpool import 2> "$OUTDIR/import-visible-error.txt" | grep -q "$POOL"; then
  warn "Pool not found in normal import list. Trying device hint scan..."
  if ! zpool import -d "$DEVICE_HINT" > "$OUTDIR/import-scan.txt" 2> "$OUTDIR/import-scan-error.txt"; then
    warn "Device scan failed. See $OUTDIR/import-scan-error.txt"
  fi
  if grep -q "$POOL" "$OUTDIR/import-scan.txt"; then
    log "Pool '$POOL' found via device hint."
  else
    warn "Pool '$POOL' still not found. Continuing with caution."
  fi
else
  log "Pool '$POOL' is visible via normal import."
fi

log "Step 2: Analyzing pool metadata with zdb..."
if ! zdb -e -bcsvL "$POOL" > "$OUTDIR/zdb-output.txt" 2> "$OUTDIR/zdb-error.txt"; then
  warn "zdb failed. Output saved to $OUTDIR/zdb-error.txt"
else
  log "zdb completed successfully. Output: $OUTDIR/zdb-output.txt"
fi

log "Step 3: Checking for dirty log state (ZIL)..."
ZPOOL_LOGSTATE=$(zpool import -l -d "$DEVICE_HINT" "$POOL" 2>&1 || true)
echo "$ZPOOL_LOGSTATE" > "$OUTDIR/zpool-logstate.txt"
if echo "$ZPOOL_LOGSTATE" | grep -q "logs with pending data"; then
  warn "Pool has uncommitted ZIL. Consider import with -FX."
  read -rp "Attempt destructive rollback using -FX (last resort)? (yes/no): " DO_FX
  if [[ "$DO_FX" == "yes" ]]; then
    log "Attempting forced rollback with -FX..."
    if ! zpool import -FX -o readonly=on -d "$DEVICE_HINT" "$POOL" > "$OUTDIR/zpool-import-FX.txt" 2>&1; then
      warn "-FX import failed. See $OUTDIR/zpool-import-FX.txt"
    else
      log "-FX import succeeded."
    fi
  fi
fi

log "Step 4: Attempting dry-run import with rollback enabled..."
DRYRUN_OUTPUT=$(zpool import -F -n -o readonly=on -d "$DEVICE_HINT" "$POOL" 2>&1 || true)
echo "$DRYRUN_OUTPUT" > "$OUTDIR/zpool-dryrun-error.txt"
if echo "$DRYRUN_OUTPUT" | grep -q "was previously in use from another system"; then
  warn "Pool was used on another system. Attempting forced read-only import."
elif echo "$DRYRUN_OUTPUT" | grep -q "cannot import"; then
  warn "Dry-run import failed. See $OUTDIR/zpool-dryrun-error.txt"
else
  log "Dry-run import succeeded."
fi

if [[ "$AUTO_IMPORT" == "yes" ]]; then
  if zpool list | grep -q "^$POOL"; then
    log "Pool '$POOL' already imported. Skipping read-only import."
  else
    log "Step 5: Performing safe read-only import..."
    if ! zpool import -F -o readonly=on -f -d "$DEVICE_HINT" "$POOL" > "$OUTDIR/zpool-import.txt" 2> "$OUTDIR/zpool-import-error.txt"; then
      warn "Read-only import failed. See $OUTDIR/zpool-import-error.txt"
    else
      log "Read-only import succeeded. See $OUTDIR/zpool-import.txt"
    fi
  fi

  log "Step 6: Listing datasets..."
  if ! zfs list -r "$POOL" > "$OUTDIR/zfs-list.txt" 2> "$OUTDIR/zfs-list-error.txt"; then
    warn "Dataset listing failed. See $OUTDIR/zfs-list-error.txt"
  else
    log "Datasets listed successfully. See $OUTDIR/zfs-list.txt"
  fi

  if [[ "$AUTO_EXPORT" == "yes" ]]; then
    log "Step 7: Exporting the pool..."
    if ! zpool export "$POOL" > "$OUTDIR/zpool-export.txt" 2> "$OUTDIR/zpool-export-error.txt"; then
      warn "Export failed. See $OUTDIR/zpool-export-error.txt"
    else
      log "Export completed successfully. See $OUTDIR/zpool-export.txt"
    fi
  else
    log "AUTO_EXPORT disabled. Pool remains imported (read-only)."
  fi
else
  log "AUTO_IMPORT disabled. No pool was imported."
fi

# --- Final Summary ---
{
echo
echo "Final Notes:"
echo "  - All operations were performed in non-destructive read-only mode."
echo "  - No datasets were mounted."
echo "  - Log and output directory: $OUTDIR"
echo "[COMPLETED]"
} >> "$REPORT"

log "Recovery script completed. Review $REPORT for details."
echo "{\"status\":\"complete\",\"pool\":\"$POOL\",\"output\":\"$OUTDIR\"}" > "$OUTDIR/summary.json"