Google's Orphaned VMs Patches Keep VMs Running While Host Kernel Goes Offline
jedisct1 · x · 2026-09-21
An experimental RFC patch series called "Orphaned VMs," led by Google engineer Pasha Tatashin, proposes letting virtual machines keep running uninterrupted — on preserved physical CPUs — while the host Linux kernel temporarily goes offline for security updates or rebooting via the Live Update Orchestrator (LUO).
Key points:
- Requires in-RAM vCPU state preservation, physical CPU preservation core support, an on-core scheduling framework, and KVM Caretaker Core infrastructure
- Tested on Intel, AMD and Arm server processors, but explicitly "very early" and not production-ready
- The series spans 46 patches, sent out for feedback from other Linux kernel stakeholders
The work targets hyperscalers' zero-downtime host maintenance push, extending kexec-based live update to running VMs.
More from Infra
- Qdrant experiments: 10→500 candidate depth lifts best-possible nDCG by 0.28 but real score by ≤0.01 — qdrant_engine · 2026-09-21
- gemini-cli PR Fixes Process Hang on Exit via stdin and MCP Child Process Cleanup — Pcmhacker-piro · 2026-09-21
- Daniel Lemire Tests Whether CPUs Can Take More Than One Branch Per Cycle — lemire · 2026-09-21
- Qwen3.8-27B in native 8-bit hits 37-55 tok/s on Apple Silicon, avoiding the 4-bit reasoning cliff — SnooPredictions515 · 2026-09-21
- djev-run Deploys DiffusionGemma on Cloud Run's RTX PRO 6000 Blackwell for ~$3/hr — bodonoghue85 · 2026-09-21
- 16GB (often 12GB) is the realistic VRAM ceiling for most people running local AI — ECrispy · 2026-09-21