Migrating from Immich on NixOS to Immich Docker

[ChocolateLoverRaj]

I was testing out Immich on my server runing NixOS using the NixOS option. It works great.

However, as I transitioned from trying out Immich to actually running Immich with everyone in my family's photos, I decided to use Docker instead of NixOS for the following reasons:

• I want to use the recommended installation method to minimize bugs / data loss
• I want to be able to upgrade Immich independently from NixOS
• From a backup/restore perspective it seemed risky. NixOS abstracts away the internals of Immich (such as upload path, postgres, redis, machine learning). Which is convenient, but seems like it could be messy. It seems like NixOS uses a single postgresql (which could be used for other programs besides Immich too) and I did not want Immich data getting mixed with other data.
• This lets me easily switch distros if needed (but I am still running NixOS and love NixOS)
• I have NixOS on a SSD and want to keep Immich on a separate disk (in my case a zfs dataset), and be able to run Immich even if I lose the OS disk.

Even though I was just "testing" Immich, I already had albums, shared links, and other people upload their photos to Immich (and I did not want them to go through the hassle of re-uploading any photos they might've moved from their phone to an external drive). So I decided to try to migrate the existing Immich on NixOS to Docker.

This took a long time and headache, so I'm posting a solution here for others to not have to spend so much time:

cd

These steps use the folder for the Docker Immich: /mnt/immich. Replace with your new folder.

cd /mnt/immich

Docker config

Same as https://immich.app/docs/install/docker-compose/, but stop before docker compose up -d. I did not change the config at all. You can change it if u want, but you might have to change the following commands to use different paths.

Migrate photo files

sudo cp -r /var/lib/immich library

Migrate postgres

sudo docker compose pull             # Update to latest version of Immich (if desired)
sudo docker compose create           # Create Docker containers for Immich apps without running them
sudo docker start immich_postgres    # Start Postgres server

Wait for the immich_postgres to finish starting (you can check with docker ps).

Then find the path to the newest database backup that was created by Immich (I had a backup from 2AM of the same day and I didn't make any changes since then. You can probably go into your NixOS Immich and create a backup job manually if needed. I tried manually creating a backup as described in https://immich.app/docs/administration/backup-and-restore#manual-backup-and-restore but it did not work.

sudo cat library/backups/immich-db-backup-1736848800029.sql.gz | gunzip | sudo docker exec -i immich_postgres psql -U postgres -d immich

Now we have to do an additional step (which I consider hacky, but it worked for me). The DB has absolute paths for files starting with /var/lib/immich. However, the Immich Docker uses /usr/src/app/upload instead. You could change docker-compose.yml to use /var/lib/immich instead of /usr/src/app/upload. I tried it and it worked. But I don't want to risk it so I did not use that method. So the solution is to replace all the strings in postgres.

sudo docker exec -it immich_postgres psql -U postgres -d immich

and then inside run (Warning: this command was generated by ChatGPT. Idk how postgres works. I tried this and it works.)

DO
$$
DECLARE 
rw RECORD;
BEGIN
    FOR rw IN 
        SELECT 'UPDATE "' || C.table_name || '" SET "' || C.column_name || '" = REPLACE("' || C.column_name || '", ''/var/lib/immich'', ''/usr/src/app/upload'');' AS QRY
        FROM (SELECT column_name, table_name 
              FROM   information_schema.columns 
              WHERE  table_schema = 'public' 
              AND    (data_type = 'text' OR data_type = 'character varying')
              AND    table_name IN (SELECT table_name 
                                    FROM   information_schema.tables 
                                    WHERE  table_schema = 'public' 
                                    AND    table_type = 'BASE TABLE')) c
    LOOP
        EXECUTE rw.QRY;
    END LOOP;
END;
$$;

It took a really long time to run

Start Immich!

sudo docker compose up -d

Advice

I would not recommend using NixOS option for running Immich (NixOS + Docker is fine) unless you're just trying it out or are fine with always using NixOS for Immich. Even with my instructions, It was hard for me to do the migration.