[Xenial] Customer can not SSH to Linux VM due to "VSC State Unhealthy"
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Incomplete
|
Undecided
|
Unassigned | ||
Xenial |
Fix Released
|
Undecided
|
Unassigned |
Bug Description
[Impact]
A mutual customer is reporting ssh is not working on a Xenial based VM. This VM is running the 4.4 based Xenial kernel and not a custom linux-azure kernel.
After an investigation this is a known old signaling issue. The 4.4 based Xenial kernels require the following patch:
vmbus: fix missing signaling in hv_signal_on_read() (https:/
The patch is not in the upstream stable 4.4 tree, because it’s not needed there.
Compared to the upstream 4.4 tree, Ubuntu 4.4.0-124-generic integrated more hv patches from the mainline kernel, e.g. Drivers: hv: vmbus: finally fix hv_need_
We checked the latest Ubuntu 4.4 kernel (https:/
The patch (13c5e97701091f
[Test Case]
When the issue happens, there is no error message in dmesg or syslog, and it's just the host side NetVSP driver stops reading from the guest-to-host ring, and the guest network stops working. So we don't really have any logs to provide here.
[Regression Potential]
Low risk since that's a simple patch from stable upstream touching only Hyper-V specific code.
CVE References
summary: |
- [Xenial] Customer could not SSH to Linux VM due to "VSC State Unhealthy" + [Xenial] Customer can not SSH to Linux VM due to "VSC State Unhealthy" |
description: | updated |
Changed in linux (Ubuntu Xenial): | |
status: | New → In Progress |
Changed in linux (Ubuntu Xenial): | |
status: | In Progress → Fix Committed |
This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1826416
and then change the status of the bug to 'Confirmed'.
If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.
This change has been made by an automated script, maintained by the Ubuntu Kernel Team.