Pick a schedule and a retention policy. Every day the schedule fires is drawn below; the filled-in ones are the copies that survive pruning. Simulated from 1 January of last year up to right now.
| Keep Last | Number of most recent snapshots to keep |
|---|---|
| Keep Daily | Number of daily snapshots to keep |
| Keep Weekly | Number of weekly snapshots to keep |
| Keep Monthly | Number of monthly snapshots to keep |
| Keep Yearly | Number of yearly snapshots to keep |
A balanced policy for most workloads:
Definitions from the ZeroByte backup docs. Each rule is applied in the order listed, newest snapshot first — and a snapshot an earlier rule already kept still uses up a later rule’s quota, which is why the counts overlap instead of adding up.
Five fields — minute hour day-of-month month day-of-week. Ranges, lists and
*/steps work, as do @daily and friends.