Tune up php.ini file

$ sudo vi /etc/php/php.ini

...
memory_limit=512M
upload_max_filesize=5G
post_max_size=5G

cgi.fix_pathinfo=0

zend_extenson=opcache

[opcache]
opcache.enable=1
opcache.intend_string_buffer=8
opcache.max_accelerated_files=10000
opcache.memory_consumption=128
opcache.save_comments=1
opcache.revalidate_freq=2
...

$ sudo systemctl restart php-fpm