Snapshot tab empty for only 1 VM

[tuxis]

Hi,

a customer of us has a VM with 9 snapshots that are not visible in the webgui.
Normally you see a line with the name "NOW" and description "You are here!" but that is also not showing for this VM.
For other VMs the snapshot function works as expected.

Both on ceph and through pvesh the snapshots are visible. However qm listsnapshot does not seem to work.
Creating new snapshots still seems to be working fine.

Version: pve-manager/6.4-14/15e2bf61 (running kernel: 5.3.13-3-pve)

qm config 101
agent: 1
balloon: 1024
boot: cdn
bootdisk: scsi0
cores: 4
description: insert long description here...
memory: 5120
name: puppet
net0: virtio=8A:A0:BD:7D:C3:B0,bridge=vmbr1,firewall=1
net1: virtio=8A:A0:BD:7D:C3:B1,bridge=vmbr999,tag=100
net2: virtio=8A:A0:BD:7D:C3:B2,bridge=vmbr999,tag=233
net3: virtio=8A:A0:BD:7D:C3:B3,bridge=vmbr999,tag=234
numa: 0
onboot: 1
ostype: l26
parent: tux
protection: 1
scsi0: ceph:vm-101-disk-0,discard=on,size=32G
scsihw: virtio-scsi-pci
smbios1: uuid=8ef68205-91b4-492f-81e9-e69136884abd
sockets: 1
tablet: 0

rbd snap ls vm-101-disk-0 --pool ceph
SNAPID NAME                            SIZE   PROTECTED TIMESTAMP               
    93 going_netplan                   32 GiB           Fri Jul 24 23:25:59 2020
   111 upgrade_ubuntu_18               32 GiB           Mon Jul 27 22:26:20 2020
   112 justbefore_netplan_apply        32 GiB           Mon Jul 27 23:35:41 2020
   113 nice_production                 32 GiB           Tue Jul 28 03:01:47 2020
   129 net_voordat_naar_ipv6_interface 32 GiB           Fri Aug  7 21:12:59 2020
   181 update                          32 GiB           Mon Sep 13 23:25:38 2021
   236 before_update                   32 GiB           Wed May 25 20:22:18 2022
   240 aaa                             32 GiB           Wed May 25 22:33:24 2022
   243 tux                             32 GiB           Mon May 30 16:05:57 2022
  
pvesh get /nodes/node01/qemu/101/snapshot
┌─────────────────────────────────────────────────┬─────────────────────────────────┬─────────────────────────────────┬
│ description                                     │ name                            │ parent                          │
╞═════════════════════════════════════════════════╪═════════════════════════════════╪═════════════════════════════════╪
│                                                 │ update                          │ net_voordat_naar_ipv6_interface │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ justbefore_netplan_apply        │ upgrade_ubuntu_18               │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ going_netplan                   │ update                          │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ tux                             │ aaa                             │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ upgrade_ubuntu_18               │ going_netplan                   │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ aaa                             │ before_update                   │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│                                                 │ net_voordat_naar_ipv6_interface │ nice_production                 │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│ Productie snapshot, nog voor prometheus install │ nice_production                 │ justbefore_netplan_apply        │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│ You are here!                                   │ current                         │ tux                             │
├─────────────────────────────────────────────────┼─────────────────────────────────┼─────────────────────────────────┼
│ apt-get update                                  │ before_update                   │ update                          │
└─────────────────────────────────────────────────┴─────────────────────────────────┴─────────────────────────────────┴

I already tried removing/renaming long descriptions & names but that does not seem to be the issue.
Does anyone have any clue on what is happening here?

BR,
Richard

 

[fabian]

there are cycles in your snapshot tree/graph:

current
  -> tux
    -> aaa
      -> before_update
        -> update
          -> net_voordat_naar..
            -> nice_production
              -> justbefore_netplan_apply
                -> upgrade_ubuntu_18
                  -> going_netplan
                    -> update (CYCLE)

the GUI and qm listsnapshots try to print this as tree and likely break on the cycle.. was there ever a manual cleanup of a failed snapshot creation or deletion? given the actual timestamps on the ceph cluster, it seems there might have been an 'update' snapshot once before (as parent of 'going_netplan'), but it was removed (both in the config and on the ceph cluster) without updating the 'parent' of 'going_netplan' in the VM config?

 

[tuxis]

I somehow overlooked this but my guess is that this history entry is somewhat related "
TASK ERROR: snapshot name 'before_update' already used".

I have manually removed a few snapshots that where the cause of the loop and the snapshot tab started to show snapshots again.
Just wanted a extra set of eyes on this. Thanks for the response Fabian.