WordPress database error: [Incorrect key file for table './pzwordpress/wp_options.MYI'; try to repair it]
UPDATE wp_options SET option_value = 'O:8:\"stdClass\":5:{s:12:\"last_checked\";i:1337441236;s:15:\"version_checked\";s:3:\"2.6\";s:8:\"response\";s:7:\"upgrade\";s:3:\"url\";s:30:\"http://wordpress.org/download/\";s:7:\"current\";s:5:\"3.3.2\";}' WHERE option_name = 'update_core'

Warning: require_once(/var/www/wordpress/wp-admin/includes/plugin.php) [function.require-once]: failed to open stream: No such file or directory in /var/www/wordpress/wp-includes/update.php on line 101

Fatal error: require_once() [function.require]: Failed opening required '/var/www/wordpress/wp-admin/includes/plugin.php' (include_path='.:/usr/share/php:/usr/share/pear') in /var/www/wordpress/wp-includes/update.php on line 101