lxd recover loses the expiration dates of snapshots.

[simondeziel]

I just went through a successful lxd recover which reimport my container and its snapshots from the intact zpool. Snapshots are taken on a schedule:

# lxc config show -e ganymede | grep snapshot
  snapshots.expiry: 3d
  snapshots.schedule: '@daily, @startup'

However, after lxd recover brought those snapshots back, they lost their expires at field:

# lxc info ganymede | sed -n '/^Snapshots:$/,$ p'
Snapshots:
+---------+----------------------+----------------------+----------+
|  NAME   |       TAKEN AT       |      EXPIRES AT      | STATEFUL |
+---------+----------------------+----------------------+----------+
| snap222 | 2024/05/07 05:28 UTC |                      | NO       |
+---------+----------------------+----------------------+----------+
| snap223 | 2024/05/08 05:28 UTC |                      | NO       |
+---------+----------------------+----------------------+----------+
| snap224 | 2024/05/09 05:28 UTC |                      | NO       |
+---------+----------------------+----------------------+----------+
| snap225 | 2024/05/09 22:21 UTC | 2024/05/12 22:21 UTC | NO       |
+---------+----------------------+----------------------+----------+

In the above, snap225 was taken after the lxd recover.

However, the instance's backup.yaml should have had this information which is where it learned about the taken at field. That said, it seems the recovery have overwritten the backup.yaml with the bogus values now:

# LD_LIBRARY_PATH=/snap/lxd/current/lib/:/snap/lxd/current/lib/x86_64-linux-gnu/ nsenter --mount=/run/snapd/ns/lxd.mnt sed -n '/^volume_snapshots:$/,$ p' /var/snap/lxd/common/lxd/storage-pools/default/containers/ganymede/backup.yaml
volume_snapshots:
- name: snap222
  description: ""
  content_type: filesystem
  created_at: 0001-01-01T00:00:00Z
  expires_at: 0001-01-01T00:00:00Z
  config:
    volatile.uuid: a951c197-c11f-4fcc-a76e-ec575b99e305
- name: snap223
  description: ""
  content_type: filesystem
  created_at: 0001-01-01T00:00:00Z
  expires_at: 0001-01-01T00:00:00Z
  config:
    volatile.uuid: 2b8f7c0c-92da-4170-af35-c5033ec6b89c
- name: snap224
  description: ""
  content_type: filesystem
  created_at: 0001-01-01T00:00:00Z
  expires_at: 0001-01-01T00:00:00Z
  config:
    volatile.uuid: dba273a7-2980-46e4-afc3-ddb7ec617171
- name: snap225
  description: ""
  content_type: filesystem
  created_at: 2024-05-09T22:21:56.762923236Z
  expires_at: 0001-01-01T00:00:00Z
  config:
    volatile.uuid: 93c48d05-4de3-492b-8e6c-f3ce2e3e9c63

Additional information:

# snap list lxd
Name  Version         Rev    Tracking     Publisher   Notes
lxd   5.21.1-d46c406  28460  5.21/stable  canonical✓  -

[simondeziel]

In fact, looking at the snap225 section of the backup.yaml (added post-recovery), it seems that during normal operations LXD doesn't save the right expires_at field in the backup.yaml file.