Database engines
Which engines OSS Panel supports, which one your server got, and how to install another from the panel.
OSS Panel manages four engines: MySQL, MariaDB, PostgreSQL and MongoDB. A server does not run all four. It runs one SQL engine — MySQL, MariaDB or PostgreSQL — and, if you want it, MongoDB alongside.
The chip row
The chips at the top of Databases are the engines, with their state and version.
A green dot means the service is up. The version comes from the engine itself, not from the panel's own list, so it is what is actually installed. An engine that is not installed appears as an Install button in the same row.
Which SQL engine you have
The SQL engine is chosen once, during first login, from the setup checklist — or by the installer, if you passed one. MariaDB is the recommended default and the right pick for WordPress and most PHP applications.
The SQL engine is a one-time choice
A server runs one SQL engine. Switching afterwards means rebuilding the server — the panel will not swap MySQL for PostgreSQL underneath your applications. Decide before you install anything that stores data.
MongoDB is different. It is a document database, so it sits next to the SQL engine rather than replacing it, and it can be added at any time.
Installing MongoDB
If MongoDB was not installed during setup, the chip row offers it.
Open Databases and find the engine chip row. Where MongoDB would be, there is an Install MongoDB button instead of a chip.
Click Install MongoDB. The panel asks once, and tells you the work happens on the server rather than in your browser.
Click Install. A progress panel replaces the dialog: a MongoDB chip appears marked Starting…, with a named stage — Downloading packages, Verifying the database connection — a progress bar, and how long it has been running.
The install genuinely continues without you. Navigating away, or closing the tab, does not cancel it.
Open Installation output if you want to watch it, or to find out why it failed. It is the real package-manager log, streamed as it is written.
Wait for the chip to turn green. On a small server this takes a couple of minutes — MongoDB pulls around 200 MB of packages and needs roughly 700 MB of disk. When it finishes, the chip shows the version and a running dot.
What installing an engine changes
The new engine is immediately offered wherever engines are chosen:
- Create a database — the Engine dropdown lists every installed engine, and only those. Before MongoDB was installed the list read MySQL, PostgreSQL; afterwards, MySQL, MongoDB, PostgreSQL.
- Database health — gains a tab for it, with its own connection, query and uptime figures.
- Services — the engine appears as a service you can stop, start and restart with the rest.
Disk, not just download
The figures in the install log are worth reading before you start on a small VPS. MongoDB 8.0 fetches about 202 MB of archives and uses about 691 MB once unpacked. Disk Cleaner in the sidebar is the place to make room first.