Php 具有多个键的多维数组输出到foreach循环

我有一个MD数组，我需要在其上运行函数以返回结果。 把它放在上下文中，它的5台服务器和1-3个硬盘驱动器可以获得可用的剩余空间

$array = array(
"Server 1" => array("C" => "85791338496", "D" => "322119397376"),
"Server 2" => array("C" => "268327448576", "E" => "536733544448", "H" => "274874757120"),
"Server 3" => array("C" => "42947571712", "E" => "214744166400"),
"Server 4" => array("C" => "64317550592", "D" => "150320705536"),
"Server 5" => array("C" => "64317550592")
);

它需要遍历每个服务器，然后遍历每个硬盘驱动器以返回可用空间。 这样做的函数在控制之下，但是基于上述数组的循环就是我被卡住的地方

foreach ($array as $server => $disks) {
    print $server .' has the following disks:';
    foreach ($disks as $disk => $avalable_space) {
        print $disk .' has '. $available_space . 'available space';
    }
}