Skip to content

Sync CNV runbook KubeVirtVMGuestMemoryPressure.md (Updated at 2025-09-15 08:41:07 +0000 UTC) #343

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
hco-bot wants to merge 1 commit into from
Closed

Sync CNV runbook KubeVirtVMGuestMemoryPressure.md (Updated at 2025-09-15 08:41:07 +0000 UTC) #343

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
69 changes: 69 additions & 0 deletions alerts/openshift-virtualization-operator/KubeVirtVMGuestMemoryPressure.md
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,69 @@
# KubeVirtVMGuestMemoryPressure

## Meaning
The VM guest OS is under sustained memory pressure (low usable memory
with elevated major page faults and/or swap I/O), risking thrashing,
swapping, or OOM kills.

## Impact
- Performance degradation due to page thrashing
- Increased swap I/O and latency
- Risk of OOM kills and application instability

## Diagnosis
- Metrics (Prometheus)
1) Identify the VMI pod (`vmi_pod` label):
```promql
kubevirt_vmi_info{vm="<vm-name>", namespace="<namespace>",
phase="running"}
```
2) Headroom (usable/available) < 5% indicates pressure:
```promql
sum by (name, namespace) (
kubevirt_vmi_memory_usable_bytes{
name="<vmi_pod>", namespace="<namespace>"
}
) /
sum by (name, namespace) (
kubevirt_vmi_memory_available_bytes{
name="<vmi_pod>", namespace="<namespace>"
}
)
```
3) Major page faults are elevated:
```promql
sum by (name, namespace) (
rate(
kubevirt_vmi_memory_pgmajfault_total{
name="<vmi_pod>", namespace="<namespace>"
}[5m]
)
)
```
4) Swap traffic is elevated (bytes/s):
```promql
sum by (name, namespace) (
rate(
kubevirt_vmi_memory_swap_in_traffic_bytes{
name="<vmi_pod>", namespace="<namespace>"
}[5m]
) +
rate(
kubevirt_vmi_memory_swap_out_traffic_bytes{
name="<vmi_pod>", namespace="<namespace>"
}[5m]
)
)
```

## Mitigation
- Short term (in guest)
- If possible, Restart or tune memory-heavy processes; reduce workload.
- If acceptable, drop caches temporarily.
- Ensure swap is sized/policy-compliant (or disabled if not desired).

- Increase VM memory (hotplug if supported; otherwise restart may be required)

If you cannot resolve the issue, log in to the
[Customer Portal](https://access.redhat.com) and open a support case,
attaching the artifacts gathered during the diagnosis procedure.