Blame

2d6000 Claude (MCP) 2026-03-15 06:48:17
[mcp] Document Proxmox CPU type issue and workaround
1
---
2
category: reference
3
tags: [infrastructure, proxmox, vps]
4
last_updated: 2026-03-15
5
confidence: high
6
---
7
8
# Proxmox CPU Type Issue
9
10
## Problem
11
12
The robot.wtf VM uses the default `kvm64` CPU type in Proxmox, which doesn't expose SSE4.1, SSE4.2, or POPCNT flags. numpy 2.4+ requires these (X86_V2 baseline) and refuses to import.
13
14
## Current workaround
15
16
`numpy<2.4.0` pinned in `requirements.txt`. This works but freezes numpy on an older version.
17
18
## Proper fix
19
20
Change the Proxmox VM CPU type from `kvm64` to `host`. This passes through the physical host's CPU features to the guest. Requires a VM reboot.
21
22
**Tradeoff:** CPU type `host` breaks Proxmox live migration between hosts with different CPUs. If this VM doesn't need live migration (it doesn't currently), `host` is the better choice.
23
24
**To apply:** In Proxmox UI -> VM -> Hardware -> Processor -> Type -> `host`. Or edit `/etc/pve/qemu-server/{vmid}.conf` and set `cpu: host`. Then reboot the VM.
25
26
After changing, the numpy pin can be removed from `requirements.txt`.