[terrywang]

Running Pi-hole on the original Pi (1) model B for over a year and really happy with it. The original Pi running Raspbian has been very reliable and working tirelessly, the only problem is the I/O bottleneck - performance querying SQLite database is unbearable.

Last Nov I spent half day installing Pi-hole on spare Pi 2 and Pi 3 (Ubuntu LTS) serving as two internal DNS Servers for home network), router (AsusWrt-Merlin) as its upstream doing DoT (DNS over HTTPS). Really happy with the performance and cost (quite, low power consumption, no heating issue, no dust collection issue, etc.)

[samus]

Does Pi-Hole also work with other SQL databases? If yes, you could host PostgreSQL on another Pi (or something beefier). Or maybe there is an adapter library that makes it possible to access another SQLite database via the network (not talking about NFS, as SQLite developers discourage from that).

[withinboredom]

I'm surprised application devs haven't done this, but you can "backup" a sqlite db to an in-memory sqlite db, then just "backup" the in-memory db every so often in the background.

[terrywang]

The problem with running Pi-hole on the Pi 1 (original) is that it does not have enough physical memory after installing pi-hole stack (I used Nginx + php-fpm for the web UI), otherwise there is way to use utils like `vmtouch` to read the sqlite database file and keep it in page cache, even "lock" it.

On Pi 2 and 3 it's no longer an issue (even if you don't do anything about it) to a memory buff and better I/O (using faster micro SD).

Pi-hole provides a mechanism to backup and rotate the database from time to time, one can do that whatever way suits their use cases.