[SOLVED] VM only working on the node it was originally installed on - VMs dont work on other nodes

[Larion]

Im testing proxmox and got surprised by the following error:

Running a 3 node hyperconverged cluster with ceph. (pve-manager/6.3-4/0a38c56f (running kernel: 5.4.101-1-pve ; last updated on 04.03.2021 nosub-repo)

I can clone VMs to the other nodes.

I can offline migrate VMs to the other nodes.

When starting a VM on another node (after they have been cloned or offline migrated) a "Start OK" is reported in the log but I get no picture in the novnc console.
No boot screen or OS, it just stays black.
It remains stuck until I forcefully shut it down with "stop vm".

all nodes identical hardware.
Cluster Quorum OK - no apparent error.
Date and Time on all nodes in sync.
All nodes can ping each other on all interfaces.
25gbase direct attached network for ceph
20gbase network (2x 10gbase) for management/migration/backup
1gbase network for corosync
20gbase network (2x 10gbase) for VM traffic but not assigned to VMs at the time of testing

VM Hardware or bios settings make no difference: machine q35 or i440; cpu kvm or epyc ; efi or legacy; no network adapter at time of test assigned;
operating system type makes no difference (tested Linux and Win10 20H2)


Any ideas ?

 

[Stoiko Ivanov]

* Does the console show up, if you connect your browser directly to the node where the VM is migrated to and started?
* Is the VM running ok? (does it respond to a ping, can you connect via ssh)?
* If not - anything relevant in the journal on both nodes?

I hope this helps!

 

[Larion]

I solved it.
was a network fragmentation issue.
Thanks anyway.

 

[Stoiko Ivanov]

Thanks for replying and explaining where the problem originated!
Please edit the thread and mark it as 'SOLVED'