Hi all,
Apologies for another post on forget policies, I’ve searched in the forum and couldn’t find my exact question, I hope I haven’t missed it.
I’m trying to make sense of a very basic forget policy:
restic forget --group-by=host,path --keep-monthly 4
My understanding is that this policy would keep only the last 4 “monthly” snapshots. That is, it would only keep the most recent snapshot for each of the last 4 calendar months that have at least 1 snapshot.
So, my first question would be, am I interpreting this correctly?
I have a repo with the following snapshots:
repository bd9a9bcc opened (version 2, compression level auto)
ID Time Host Tags Paths
----------------------------------------------------------------
8910a903 2024-01-02 13:42:44 myhost mytag /tmp/data
ab49e6f7 2024-01-03 01:04:38 myhost mytag /tmp/data
209e47d4 2024-01-04 20:09:54 myhost mytag /tmp/data
acdde683 2024-01-04 20:20:32 myhost mytag /tmp/data
----------------------------------------------------------------
4 snapshots
If I understood correctly, that forget policy would remove all but the last snapshot (acdde683), since all of them were taken in the same calendar month. However, I get the following result:
repository bd9a9bcc opened (version 2, compression level auto)
Applying Policy: keep 4 monthly snapshots
snapshots for (host [myhost], paths [/tmp/data]):
keep 2 snapshots:
ID Time Host Tags Reasons Paths
----------------------------------------------------------------------------------
8910a903 2024-01-02 13:42:44 myhost mytag monthly snapshot /tmp/data
acdde683 2024-01-04 20:20:32 myhost mytag monthly snapshot /tmp/data
----------------------------------------------------------------------------------
2 snapshots
remove 2 snapshots:
ID Time Host Tags Paths
----------------------------------------------------------------
ab49e6f7 2024-01-03 01:04:38 myhost mytag /tmp/data
209e47d4 2024-01-04 20:09:54 myhost mytag /tmp/data
----------------------------------------------------------------
2 snapshots
Would have removed the following snapshots:
{209e47d4 ab49e6f7}
What is the reason for also keeping the first snapshot (8910a903)?
In case it helps, I’m using restic version 0.16.2 compiled with go1.21.3 on linux/amd64 and I used the following script to create the repo:
#!/bin/bash
mkdir -p /tmp/{repo,data}
touch /tmp/data/foo
export RESTIC_PASSWORD="1234"
restic init -r /tmp/repo
restic backup -r /tmp/repo --time="2024-01-02 13:42:44" --tag="mytag" /tmp/data
restic backup -r /tmp/repo --time="2024-01-03 01:04:38" --tag="mytag" /tmp/data
restic backup -r /tmp/repo --time="2024-01-04 20:09:54" --tag="mytag" /tmp/data
restic backup -r /tmp/repo --time="2024-01-04 20:20:32" --tag="mytag" /tmp/data
restic snapshots -r /tmp/repo
restic forget --dry-run --verbose=2 -r /tmp/repo --host $(hostname) --group-by=host,path --keep-monthly 4
PS. I’m really liking restic, many thanks for the hard work!
Thanks!
