VMs Lose Network Connectivity After Upgrade (Ubuntu 22/24 LTS Nodes)

Symptoms

Following a SolusVM 2 upgrade, VMs experience a network outage. The network briefly appears functional immediately after the upgrade, then fails once a Virtual Server is started, restarted, or created.

Cause

The SolusVM 2 upgrade process restarts the OVS (Open vSwitch) service, which clears all existing flow rules on the host. This leaves the host briefly functional but unprotected, with no ARP whitelist rules in place.

As soon as any Virtual Server is started, restarted, or created, ARP rules operating in whitelist mode are applied for that Virtual Server. Because the OVS restart removed all existing whitelist rules, traffic for Virtual Servers that have not yet had their rules reapplied is treated as non-whitelisted and is dropped, resulting in the network outage.

The case has been submitted as a product issue with the internal ID SVM2-6538. 

Resolution

This issue has been permanently fixed in SolusVM 2 version 2.0.0-42604 (released 2026-07-09). 

Network rules now automatically reapply after the Open vSwitch service restarts on a Compute Resource, preventing the connectivity outage described above.

Updating to version 2.0.0-42604 or later resolves this issue. See the Release Notes for details.