很久以前還在用 php5 + wordpress 時，文章的縮圖都有自動被產生，某一次升級之後，縮圖功能就不見了。花了2小時Google 終於找到原因。

解法如下：

apt-get install php7.0-gd
phpenmod gd
/etc/init.d/php7.0-fpm restart

php restart 不同平臺的下法：

• Using SysV Init scripts directly:

  /etc/init.d/php-fpm restart    # typical
  /etc/init.d/php5-fpm restart   # debian-style
  /etc/init.d/php7.0-fpm restart # debian-style PHP 7
   
  

• Using service wrapper script

  service php-fpm restart    # typical
  service php5-fpm restart   # debian-style
  service php7.0-fpm restart # debian-style PHP 7
  

• Using Upstart (e.g. ubuntu):

  restart php7.0-fpm         # typical (ubuntu is debian-based) PHP 7
  restart php5-fpm           # typical (ubuntu is debian-based)
  restart php-fpm            # uncommon
   
  

• Using systemd (newer servers):

  systemctl restart php-fpm.service    # typical
  systemctl restart php5-fpm.service   # uncommon
  systemctl restart php7.0-fpm.service # uncommon PHP 7

我試了上面，重啟 apache2 + php7-fpm 之後，還是無效，刪掉放在我 wordpress 根目錄裡的 composer.json ＋ composer.lock ，再重啟一次之後，重新產生縮圖，就看到縮圖跑出來了!