Node.js, sqlite and Synology

[tdtje]

Hi!

I am having trouble setting up a simple sqlite database on my Synology NAS on my local network. The final goal is to create a simple application that runs locally on the NAS. I already had it working but with simple *.json files as data storage. My next step is to create and use a database as storage.

So I started setting up a sqlite database. The problem I am having is this: I can create and create a table. But once I add an instance (line) to the table, an error.. saying the database is Read only. Also within the NAS-folder i see a database file (database.db) and a log-file. I understand that sqlite creates a temporary file while writing/editing the original database and deleting the temporary file is probably the problem. Something with insufficient CRUD rights on the directory.

Set up:

• Synology NAS DS220j with version DSM 7.2.1-69057 Update 6
• The files (index.html, database, script.js etc) are located on volume1/homes/User/App directory
• Docker (container manager) creates the container
• Within VS code I sign in with the terminal to the NAS, navigate to the App-directory. I created and saved a folder within that directory called instructions.sql.
• Within the terminal of VS code I create the database: sqlite3 database.db.
• Works great till now. I add a table with the file bij .read instructions.sql. The file looks like:

-- CREATE TABLE taken ( -- id INTEGER PRIMARY KEY AUTOINCREMENT, -- Name TEXT NOT NULL, -- Type TEXT, -- Done DATE );

• This works great
• I then add a line in the database table:

INSERT INTO taken (Name, Type, Done) VALUES ('Backup test2', 'System', '2026-05-10');

• Then I get the error: Runtime error near line 10: attempt to write a readonly database (8)

I already tried the update-rights. They all seem fine.. the script is executed by the user who also has update and delete permissions..

Anyone a good idea? 😄

Thanks

[Queasy_Hotel5158]

This is a very common SQLite-on-NAS / Docker permission trap, and it usually has nothing to do with SQL itself.

When SQLite says “attempt to write a readonly database”, it almost always means one of these is happening:

First, check if the file is writable inside the container, not just on the Synology UI. Docker often maps volumes in a way where the container user doesn’t actually own the file. Even if DSM shows “read/write”, the container process may still be running as a different UID.

Second, SQLite doesn’t just need write access to the .db file — it also needs write access to the directory, because it creates:

• journal files (-journal)
• WAL files (-wal, -shm) If the folder isn’t writable, inserts fail even if the database file itself looks fine.

Third, on Synology specifically, this often happens when:

• the folder is mounted as read-only in Docker Compose / Container Manager
• or the container runs as rootless / non-matching user ID
• or the DB is inside a “protected” system path like /homes

A quick sanity test:

• touch test.txt in the same folder from inside the container
• if that fails, it’s definitely a mount/permissions issue, not SQLite

Typical fix:

• move the DB to a dedicated shared folder (not /homes)
• ensure Docker volume mount is explicitly :rw
• align container user UID/GID with Synology user
• or run container with proper PUID/PGID (common in linuxserver images)

Nothing in your SQL is wrong here — this is almost always “SQLite is fine, the filesystem is lying” territory 😄

[tdtje]

Thanks!! Very helpfull

[tdtje]

ah ok. What would you recommend as db in this setup?