Hi! I was trying to set up my backups with kopia. Surprisingly, the biggest problem was understanding how retention policies work. Lack of documentation on this topic doesn’t really help. So I searched the forums and Reddit and all that. I think I read every post regarding that, and I think I kinda…

It is actually very handy - thank you!

[image] JayKay729: Kopia deletes snapshots that do not have a label. So it works like an OR operator, that as long as the snapshot passes even a single retention policy, it’s kept. It is only deleted if it fails all of them. Did I understood it correctly? Like for example, if I only want to …

I’m pretty sure that’s how it works :slight_smile:

Thanks! About whether the week starts on Monday or Sunday, according to this post , it seems to be based on duration instead? That unless you retain backups that have at least a 7-day gap, weekly snapshot would be completely useless. Also, based from the example given by this user , the duration is c…

I just checked one of my machines and the the weekly one is always from Sunday (I run one backup at 1:00 every day) 2024-03-31 01:00:04 UTC k26ff5face32a58d46760765d2ad2785d 2.6 GB drwxr-xr-x files:8367 dirs:537 (monthly-2) 2024-04-14 01:00:05 UTC k76360b4b9ca1eb7021400412a5a9ac06 2.7 GB drwxr-xr…

[image] JayKay729: the weekly one is always from Sunday (I run one backup at 1:00 every day) But 2024-03-31 is a Sunday. Have you tried what happens if the oldest snapshot isn’t a Sunday?

Oh yeah. That’s the issue with testing this because you actually have to wait a year to find out what “annual” does lol Honestly, I rewrote this very message you’re reading right now like 5 time in 30 mins (this really shouldn’t be this complicated, haha). Could you please restate your argument fro…

[image] JayKay729: Could you please restate your argument from the beginning? I think I don’t know what we’re discussing anymore haha That weekly snapshots seems to not be based from Sunday or Monday, but from the oldest snapshot. That if for example, the oldest snapshot you have retained is …

I’ve checked when the first first snapshot was taken. It was on the 6th of March which is a Wednesday. It obviously got deleted as it went out of range for daily and weekly and monthly tags. Theoretically you could run an experiment on Saturday. Run snapshots daily, and check on Monday if the weekly…

After several tests, I have confirmed your findings: it was indeed Sunday. Kopia considers Monday to Sunday as a week (as opposed to Sunday to Saturday), and the weekly tag is attached to the snapshot closest to Sunday 11:59 PM.

Retention policies documentation

Support

rhinomagnetar May 27, 2024, 10:54am 12

Btw here’s a more comprehensive post I made regarding retention policies:

Topic		Replies	Views
Trying to understand retention policies Support	12	4965	April 30, 2024
Trying to understand retention policies - cont General	13	2717	November 21, 2024
Kopia retention policy Support	2	637	July 13, 2021
Snapshot Retention Explanation - for a 7 year old General Topics	2	400	July 22, 2024
Kopia Snapshot Retention Policies Demystified Support	12	2526	December 22, 2024

Retention policies documentation

Related topics