Zip files in a streamable way, with a 2MB memory footprint.

stream_zip.php

<?php
// composer init; composer require maennchen/zipstream-php
error_reporting(-1);
require_once __DIR__ .'/vendor/autoload.php';

function stream_zip( array $files, string $out_file ) {
	$out = fopen( 'file://' . $out_file, 'w' );

	$options = new ZipStream\Option\Archive();
	$options->setOutputStream( $out );

	$zip = new ZipStream\ZipStream( 'zipstream.zip', $options );
	foreach ( $files as $file ) {
		$in = fopen( 'file://' . __DIR__ . "/{$file}", 'rb' );
		$zip->addFileFromStream( $file, $in );
		fclose( $in );
	}
	$zip->finish();
	fclose($out);

	echo ( memory_get_peak_usage( false ) / 1024 / 1024 ) . " MiB\n";
}

stream_zip( [ 'box-disk001.vmdk' ], __DIR__ . '/sander.zip' );

for a 5GB file: 2.9 MiB Memory used.