Reinstalling from USB stick but without removing existing ZFS pool.

mattbirch

Hi there,

Short background. I manage to break my GhostBSD install. Its not completely "destroyed".
I have manage to boot in to single user mode and set a root password as I have forgotten that and forgot to write it down.

I have manage to via GhostBSD USB stick created recursively snapshots for the ZFS pool zroot once the installer was booted up.

So I wonder is there any way of using the installer to not wipe all the datasets or perhaps rename the datasets so that I can reinstall GhostBSD and then once that is done I can mount the other ZFS datasets on other mount points and move my data around on to the newly create datasets via the installer.

Or that option does not exist in the installer and I have to some how backup my datasets and reinstall as it can't install to an existing zpool (The installer that is)?

I don't know if my upgrade broke the system because it was fetching incomplete packages or something similar to that effect. I'm not 100 % sure why my system sort of broke.

In any case I can provide more detailed information of there is any interest.

I create a (type)script file ... perhaps I can get that from the system so one can more in detail see what went wrong with the upgrade.

Thank you.

BR - Matt Birch

vimanuelt

mattbirch
Below is a GhostBSD ZFS Recovery Toolkit script. You can give it a try.


    #!/bin/sh
    # File: zfs-recovery-tool.sh
    # GhostBSD ZFS Recovery Toolkit – With Single-User Mode Awareness and Logging
    

    set -eu
    

    ### --- Configuration ---
    OLD_POOL="zroot"
    RENAMED_POOL="oldzroot"
    SNAP_NAME="preinstall"
    BACKUP_DISK="/mnt/backup"
    IMPORT_MNT="/mnt/old"
    LOGFILE="/tmp/zfs-recovery.log"
    TIMESTAMP=$(date +%Y%m%d_%H%M%S)
    

    ### --- Environment Detection ---
    IS_SINGLE_USER=0
    if [ "$(sysctl -n kern.singleuser 2>/dev/null || echo 0)" = "1" ]; then
      IS_SINGLE_USER=1
    fi
    SUDO=sudo
    [ "$IS_SINGLE_USER" = "1" ] && SUDO=""
    

    ### --- Logging Helper ---
    log() {
      echo "$@" | tee -a "$LOGFILE"
    }
    

    ### --- Environment Validation ---
    ensure_environment_ready() {
      [ "$IS_SINGLE_USER" = "1" ] && {
        mount -u / 2>/dev/null || true
        mount -a 2>/dev/null || true
      }
    

      for cmd in zfs zpool gzip; do
        if ! command -v "$cmd" >/dev/null 2>&1; then
          echo "[!] Required command '$cmd' not found. Make sure /usr is mounted."
          exit 1
        fi
      done
    }
    

    check_backup_disk_mounted() {
      if ! mount | grep -q "$BACKUP_DISK"; then
        echo "[!] $BACKUP_DISK is not mounted."
        echo "    Mount it first: $SUDO mount /dev/da1s1 $BACKUP_DISK"
        exit 1
      fi
    }
    

    confirm() {
      echo -n "$1 [y/N]: "
      read resp
      [ "$resp" = "y" ] || exit 1
    }
    

    ### --- Toolkit Operations ---
    

    reset_root_password() {
      ensure_environment_ready
      log "[*] Launching root password reset..."
      passwd root && log "[✔] Password updated." || { log "[!] Password change failed."; exit 1; }
    }
    

    rename_pool() {
      ensure_environment_ready
      if ! zpool list | grep -q "^$OLD_POOL"; then
        echo "[!] Pool '$OLD_POOL' not found."
        exit 1
      fi
      confirm "Rename pool '$OLD_POOL' to '$RENAMED_POOL' to prepare for reinstall?"
      zpool export "$OLD_POOL"
      zpool import -R /mnt "$OLD_POOL" "$RENAMED_POOL"
      log "[✔] Pool renamed successfully as '$RENAMED_POOL'."
    }
    

    reimport_old_pool() {
      ensure_environment_ready
      $SUDO mkdir -p "$IMPORT_MNT"
      $SUDO zpool import -R "$IMPORT_MNT" "$RENAMED_POOL"
      $SUDO zfs list -r "$RENAMED_POOL"
      log "[✔] Pool '$RENAMED_POOL' available at $IMPORT_MNT."
    }
    

    backup_datasets() {
      ensure_environment_ready
      check_backup_disk_mounted
    

      for DATASET in $(zfs list -H -o name -r "$OLD_POOL"); do
        SNAP="$DATASET@$SNAP_NAME"
        SAFE_NAME=$(echo "$DATASET" | sed 's|/|_|g')
        FILE="$BACKUP_DISK/${SAFE_NAME}__${SNAP_NAME}_${TIMESTAMP}.zfs.gz"
    

        if zfs list -t snapshot "$SNAP" >/dev/null 2>&1; then
          log "[*] Backing up $SNAP to $FILE"
          zfs send "$SNAP" | gzip > "$FILE"
        else
          log "[!] Snapshot $SNAP not found. Skipping."
        fi
      done
      log "[✔] Backup complete."
    }
    

    restore_datasets() {
      ensure_environment_ready
      check_backup_disk_mounted
      confirm "Restore datasets from $BACKUP_DISK to pool '$OLD_POOL'?"
    

      if ! zpool list | grep -q "^$OLD_POOL"; then
        zpool import "$OLD_POOL"
      fi
    

      for FILE in "$BACKUP_DISK"/*.zfs.gz; do
        log "[*] Restoring from $FILE..."
        gunzip -c "$FILE" | zfs recv -Fdu "$OLD_POOL"
      done
    

      log "[✔] Restore complete."
    }
    

    ### --- CLI Mode ---
    if [ "$#" -gt 0 ]; then
      case "$1" in
        --reset-password) reset_root_password ;;
        --rename-pool) rename_pool ;;
        --reimport-pool) reimport_old_pool ;;
        --backup) backup_datasets ;;
        --restore) restore_datasets ;;
        --help|-h)
          echo "Usage: $0 [--reset-password|--rename-pool|--reimport-pool|--backup|--restore]"
          exit 0 ;;
        *) echo "[!] Unknown option: $1" ; exit 1 ;;
      esac
      exit 0
    fi
    

    ### --- Interactive Menu ---
    while :; do
      echo
      echo "GhostBSD ZFS Recovery Toolkit"
      echo "=============================="
      echo "  0) Reset root password"
      echo "  1) Rename pool before reinstall"
      echo "  2) Reimport preserved pool"
      echo "  3) Backup datasets to external disk"
      echo "  4) Restore datasets from backup"
      echo "  5) Exit"
      printf "Choice [0-5]: "
      read CHOICE
      case "$CHOICE" in
        0) reset_root_password ;;
        1) rename_pool ;;
        2) reimport_old_pool ;;
        3) backup_datasets ;;
        4) restore_datasets ;;
        5) echo "Exiting. Log written to $LOGFILE" ; exit 0 ;;
        *) echo "[!] Invalid choice." ;;
      esac
    done
```

vimanuelt

Usage Instructions

(1) Save the Script

Save the script above as: zfs-recovery-tool.sh

Then make it executable: chmod +x zfs-recovery-tool.sh

(2) Run Interactively (Recommended)

Run it from the Live USB or single-user mode:

sudo ./zfs-recovery-tool.sh

This will show a menu:

GhostBSD ZFS Recovery Toolkit
==============================
  0) Reset root password
  1) Rename pool before reinstall
  2) Reimport preserved pool
  3) Backup datasets to external disk
  4) Restore datasets from backup
  5) Exit

(3) Run with Command-Line Options

You can use it non-interactively:

sudo ./zfs-recovery-tool.sh --reset-password
sudo ./zfs-recovery-tool.sh --rename-pool
sudo ./zfs-recovery-tool.sh --backup
sudo ./zfs-recovery-tool.sh --restore

(4) Create a Snapshot Before Backup

Before using the backup feature, run: zfs snapshot -r zroot@preinstall

(5) Mount External Backup Disk

Make sure your disk is mounted at /mnt/backup:

sudo mkdir -p /mnt/backup
sudo mount /dev/da1s1 /mnt/backup

Replace /dev/da1s1 with the correct device name.

(6) View Logs

All operations are logged to: /tmp/zfs-recovery.log

You can view it with: less /tmp/zfs-recovery.log

Summary

Use Option 0 for forgotten password recovery
Use Option 1 to protect existing datasets during reinstall
Use Option 2 to reimport a preserved pool
Use Option 3 to export data to external disk
Use Option 4 to restore data to a fresh GhostBSD install