Failed to start php-fpm.service: Unit not found.

1 查找 php-fpm

find / -name init.d.php-fpm

/root/php-7.4.4/sapi/fpm/init.d.php-fpm

2 执行

cp /root/php-7.4.4/sapi/fpm/init.d.php-fpm /etc/init.d/php-fpm

chmod a+x /etc/init.d/php-fpm