Oct 14, 2026, 9:54 PMMe, 4PM: "dang it, why is my incremental zfs send of /var/mysql sending the entire file instead of just the changes from yesterday???"
Me, now: "Oh. The contents of /var/mysql churn 99% between yesterday and today."
Anyway, I'm working hard on #openzfsmastery. I'd appreciate your support. https://mwl.io/sponsor
Oct 14, 2026, 9:56 PMthis is, of course, a great example for the book! And probably will be my example of snapshot redaction.
When I fail to make words, it's because I'm gaining (ugh) experience. :flan_XD: :flan_piteous:
@mwl I heard this somewhere, "Experience is what you get when you don't have it when you need it." ;)
Oct 15, 2026, 6:41 AM@mwl any particular reason to have /var/mysql, assuming that's the DB dir, on zfs?
Oct 15, 2026, 12:32 PM@kaveman definitely put your database on ZFS!
Adjust recordsize to match the db block size, select the caching to match what your database doesn't optimize for, plus free snapshots and replication etc.
Oct 15, 2026, 12:49 PM@mwl interesting! I'd still hesitate to replicate because of WAL files etc.it would be safer to delegate to the db engine for replication. I think.
Oct 15, 2026, 12:53 PM@kaveman seriously, do both. Live replication in the cluster, zfs snapshots & replication for backups & DR
Oct 15, 2026, 6:56 PM@mwl I'll keep that in mind. The hesitation comes from potential write amplification but then again haven't managed heavy-workload databases in 20 years so I'll take your word.
Oct 15, 2026, 7:43 PM@kaveman you can absolutely cause write amplification through misconfiguration!
But if you tune it correctly, it's screaming fast