Opterius runs PHP via PHP-FPM with a dedicated pool per domain. Each pool runs under its own PHP version, which means domains on the same account — or across different accounts — can run different PHP versions at the same time with no interference between them.
Supported Versions
- PHP 8.1
- PHP 8.2
- PHP 8.3
- PHP 8.4
All versions are installed system-wide by the server admin. If a version is not available in your dropdown, ask your admin to install it. See Installing PHP Versions.
How It Works
Each domain gets a PHP-FPM pool config at:
/etc/php/{version}/fpm/pool.d/{domain}.conf
The domain's Nginx vhost points fastcgi_pass at that pool's Unix socket. When you switch a domain's PHP version, the agent rewrites the pool config file, creates the pool under the new version's FPM, and updates the Nginx vhost — then reloads both. The old pool is shut down.
Switching a Domain's PHP Version
Go to Hosting Mode → PHP → [domain] → PHP Version → [select version] → Save.
The switch is immediate with a graceful reload — no requests are dropped. See Switching PHP Version for the full step-by-step.
Multiple Domains, Multiple Versions
You can run any combination across domains:
| Domain | PHP Version |
|---|---|
| example.com | 8.3 |
| legacy-app.example.com | 8.1 |
| staging.example.com | 8.4 |
Each domain's FPM pool is isolated. Changing the PHP version or php.ini values on one domain has no effect on the others.
[!NOTE] PHP CLI (used in cron jobs and SSH sessions) is a separate binary from PHP-FPM. If your cron job needs a specific PHP version, call it explicitly:
/usr/bin/php8.3 /path/to/script.php