PHP Scripts that can help you debug and remove huge (order of 10million files) directories.

ls.php

<?php

// get the file count, because `ls |wc -l` will not complete in reasonable time

// usage: php ls.php path/

$path = $argv[1];
$dir = opendir($path);
if (!$dir) {
	echo "unable to open dir\n";
	exit(1);
}

$i = 0;
while (false !== ($entry = readdir($dir))) {
	++$i;
	if ($i % 100 === 0)
		echo "\r$i";
}
echo "\r$i\n";
closedir($dir);

rm.php

<?php

// remove all files in the directory matching a pattern
// CAUTION: THIS HAS NOT BEEN TESTED WELL, USE AT OWN RISK, HAVE A BACKUP!

// usage: php rm.php path/

$path = $argv[1];
echo "deleting files in $path\n";
$dir = opendir($path);
if (!$dir) {
	echo "unable to open dir\n";
	exit(1);
}

$i = 0;
while (false !== ($entry = readdir($dir))) {
	//if ($entry != "." && $entry != "..") {
	//	echo $entry . "\n";
	//}
	if (strpos($entry, 'sess_') === 0) {
		unlink("$path/$entry");
		++$i;
		if ($i % 100 === 0) {
			echo "\r$i";
			usleep(100000);
		}
	}
	if ($i % 1000 === 0) usleep(500000);
}

closedir($dir);