Enable multi-threaded gzip

[Cristy94]

I am trying to migrate my Coolify instance, but gzipping 100GB takes forever (already waiting for 20+ minutes).
I noticed a single thread is being used.

ChatGPT suggested this solution:

Yes. Use pigz for compression and decompression. Minimal edits:

1) Source: create the archive with pigz if available

# choose compressor
if command -v pigz >/dev/null 2>&1; then
  echo "✅ Using pigz for parallel gzip"
  # SC2086 intentional for $volumePaths
  tar -Pcf - -C / "$backupSourceDir" "$HOME/.ssh/authorized_keys" $volumePaths | pigz > "$backupFileName"
else
  echo "ℹ️ pigz not found, using gzip"
  # SC2086 intentional for $volumePaths
  tar -Pczf "$backupFileName" -C / "$backupSourceDir" "$HOME/.ssh/authorized_keys" $volumePaths
fi

2) Remote: install pigz and extract via pigz -dc | tar -Px

In your remoteCommands block, add a pigz check/install next to curl, then replace the extraction line.

  echo '🚸 Checking if pigz is installed...';
  if ! command -v pigz >/dev/null 2>&1; then
    echo 'ℹ️ Installing pigz...';
    if [ -f /etc/debian_version ] || { [ -f /etc/os-release ] && grep -iq "raspbian" /etc/os-release; }; then
      apt-get update && apt-get install -y pigz || { echo '❌ pigz install failed'; exit 1; }
    elif [ -f /etc/redhat-release ]; then
      yum install -y pigz || { echo '❌ pigz install failed'; exit 1; }
    elif { [ -f /etc/SuSE-release ] || { [ -f /etc/os-release ] && grep -iq "suse" /etc/os-release; }; }; then
      zypper install -y pigz || { echo '❌ pigz install failed'; exit 1; }
    elif [ -f /etc/arch-release ]; then
      pacman -Sy --noconfirm pigz || { echo '❌ pigz install failed'; exit 1; }
    elif [ -f /etc/alpine-release ]; then
      apk add --no-cache pigz || { echo '❌ pigz install failed'; exit 1; }
    else
      echo '❌ Unsupported OS for pigz install'; exit 1;
    fi
  fi
  echo '✅ pigz ready';

  echo '🚸 Extracting backup file...';
  if ! pigz -dc | tar -Px -C / ; then
    echo '❌ Backup file extraction failed'; exit 1;
  fi
  echo '✅ Backup file extracted';

3) Optional: simpler tar -I pigz variant

If you prefer a single tar command and GNU tar is guaranteed:

# create
tar -I pigz -Pcf "$backupFileName" -C / "$backupSourceDir" "$HOME/.ssh/authorized_keys" $volumePaths
# remote extract (still best to use pigz -dc for parallel decode)
pigz -dc | tar -Px -C /

4) Note on volume paths

Docker volume data is under .../volumes/<name>/_data. Ensure you append /_data when building $volumePaths, or you’ll archive metadata directories, not the contents.

This change keeps your streaming workflow intact and accelerates both compression and decompression.