docs: document DB_STORAGE_TYPE environment variable

[ramonsmits]

Description

Document DB_STORAGE_TYPE, I was pointed to this setting on Discord:

https://github.com/immich-app/immich/blob/main/docker/docker-compose.yml#L65-L66`

How Has This Been Tested?

1. Added envvar to docker compose
2. Started it
3. Observed mmich_postgres | Using HDD storage in the logs indicating the envvar was found and used.

Checklist:

NA, no code change, only docs update.

[danieldietzler]

I was considering adding an explanation there but I guess people don't actually care about the technical background/what it does.

[ramonsmits]

I was considering adding an explanation there but I guess people don't actually care about the technical background/what it does.

I can add it but I don't know what is controls. I would actually want to know :-)

[aviv926]

I was considering adding an explanation there but I guess people don't actually care about the technical background/what it does.

I can add it but I don't know what is controls. I would actually want to know :-)

See here: https://github.com/immich-app/immich/releases/tag/v1.133.0

[mmomjian]

Can you please follow the syntax with square brackets as in other ENV options?

No need to write out the default, we have a column for that.

[danieldietzler]

@aviv926 I don't think that page explains it at all? It chooses which of the two postgresql.conf to use from here https://github.com/immich-app/base-images/tree/main/postgres

[ramonsmits]

Can you please follow the syntax with square brackets as in other ENV options?

Done

Also added information to what it actually does as @danieldietzler also hinted.

[aviv926]

@aviv926 I don't think that page explains it at all? It chooses which of the two postgresql.conf to use from here https://github.com/immich-app/base-images/tree/main/postgres

I thought he was looking for the simple explanation as explained in the release notes.

Why does it matter whether my database is on an SSD or an HDD?
These storage mediums have different performance characteristics. As a result, the optimal settings for an SSD are not the same as those for an HDD. Either configuration is compatible with SSD and HDD, but using the right configuration will make Immich snappier. As a general tip, we recommend users store the database on an SSD whenever possible.