A side note on pgBackRest: PGX created a fork and announced to maintain it under the name pgxbackup:

https://thebuild.com/blog/2026/05/01/pgxbackup-continuity-su...

It looks like pgBackRest will likely continue, multiple companies are stepping up with sponsorships. Mentioning this just in case anyone is making plans to move away, it's probably worth waiting a bit for things to settle.

> We use Barman inside Kubernetes via CloudNativePG's plugin, as it is the default backup plugin.

right and here's why CloudNativePG chose Barman over pgBackRest: https://github.com/cloudnative-pg/cloudnative-pg/issues/3077

> WAL limits need to be set carefully or you just end up filling WAL volumes and the database becoming unavailable.

This is true. For anyone getting alarmed that this is due to a bug in PostgreSQL, it's not - it's PostgreSQL protecting the customer from attempting to write data that it cannot durable commit - "I am going to go unavailable because I don't have enough space to save more data".

There are multiple ways to handle this, the easiest, most hands on way is to keep a monitor and alert that watches the WAL size like a hawk and then alerts OPS the moment it breaches a threshold.

Something like Rclone and a cron job, or else s3 mounted via FUSE, could possibly bridge that. Of course then you have to worry about reliability of the bridge...