If you like, you can give me access to the Grafana dashboard so I can take a look and we can take it from there. It’s going to be totally free of charge of course as I am quite interested in your problem: it’s both a challenge for me and helping a fellow Lemmy user. The only thing I ask is that we report back the results and solution here so that others can benefit from the work.

No problem. PM me an IP (v4 or v6) or an email address (disposable is fine) and I’ll reply with a link to access Grafana with above in allow list.

I guess I could just use rsync to periodically sync RAM drive to disk or just rely on backups to restore running state in case of failure or just a restart. On a mostly idle server with few users this could probably work, but I don’t think I’m quite ready for such a risky setup. Server is still perfectly usable at 15% iowait - i was just hoping I could reduce it with mechanisms built into PSQL. Appreciate the suggestion though.

Edit: I just want to say this would be an awesome feature for Docker/Podman to have an in-memory volume that syncs to disk either periodically or on container termination as an option.

• I never manually VACUUMed the DB. I just assumed it does it automatically at regular intervals. VACUUMing manually didn’t seem to make any difference and gave me the following error after a few minutes of running on various tables: ERROR: could not resize shared memory segment "/PostgreSQL.1987530338" to 67128672 bytes: No space left on device I’m not 100% sure where it out of space, but I’m assuming one of the configured buffers since there was still plenty of space left on disk and RAM. I didn’t notice any difference in iowait while it was running or after.
• Yes, seeding is mostly inserts, but I see a roughly equal number of selects. I did increase shared_buffers and effective_cache_size with no effect.
• https://ctxt.io/2/AABQciw3FA https://ctxt.io/2/AABQTprTEg https://ctxt.io/2/AABQKqOaEg

I did install Prometheus with PG exporter and Grafana. I’m not a DB expert and certainly not a PostgreSQL expert, but I don’t see anything that would indicate an issue. Anything specific you can suggest that I should focus on?

Thanks for all the suggestions!

I’ll try adjusting wal_buffers.

I think I was hoping there’s s magic setting that would allow psql to operate more like Redis that uses ram for everything until it dumps it to disk at specific intervals.