[SOLVED] Proxmox inside Proxmox?

Fred Saunier

Well-Known Member
Aug 24, 2017
55
2
48
Brussels, BE
Hi all,

This used to be a non-issue, only this time around with proxmox 6.2, things are not so straight (at least for me).

I need to install Proxmox 6.2 as a VM inside a Promox 6.2 hypervisor, to run a series of tests. I cannot seem to get a network connection. In the past, I did this a number of times with proxmox 4.4, and it was easy as 1-2-3. Today, I can find "Proxmox inside VirtualBox" in the wiki, but nothing relative to "Proxmox inside Proxmox". No network, the thing cannot even ping itself.

I tried VirtIO network and Intel e1000, to no avail.

Any pointers most welcome :)

Fred
 
Inside the VM - what's the output of:
Code:
ip link
ip addr
ip route
ping $gateway
(where you replace $gateway by your gateway ip)

What's the VM config of the PVE guest?
 
I'll have to post screenshots, as I cannot copy from console

Screenshot.png

vm config:
agent: 1
bootdisk: scsi0
cores: 4
ide2: none,media=cdrom
kvm: 0
memory: 8192
name: px-test1
net0: virtio=E2:76:96:A5:13:F0,bridge=vmbr0,tag=10
numa: 0
ostype: l26
scsi0: POOL_HDD:vm-5001-disk-0,backup=0,cache=writeback,discard=on,size=100G
scsihw: virtio-scsi-pci
smbios1: uuid=0a8d54f2-8614-4837-ae0a-dc4cd6f0f323
sockets: 2
vga: qxl
vmgenid: 91cc96a5-f549-414c-806a-f025cc379512
 
The network config looks ok - is 192.168.10.1 reachable in vlan 10 from the vmbr0 of the physical (outside) PVE-host?
 
In vlan 10?
else - I would suggest to start checking with tcpdump where the packets get lost

I just spun a live Ubuntu on the same hypervisor, in VLAN 10 -- it is getting an IP from the dhcp, and can go out through the vlan gateway. So my little LAB VLAN looks okay.

I'll get a new copy of the iso, and re-install proxmox and see what it says.
 
Found the cause of the issue. Turns out I had set KVM hardware virtualization to no. Setting it back to yes allows network connections.

I thought I remembered from the past that KVM hardware virtualization has to be set to no for nested pve, but I remembered wrong. It can be set to yes, then nested vms inside the virtualized pve have the option set to no.

Now it works.
 
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Reactions: Stoiko Ivanov
Glad you resolved your issue - still seems a bit odd that kvm should change the way the network devices work - but if it works now :)

regarding nested virtualization - this can be tricky in clustered setups (migrating guests which are hypervisors themselves does not work reliably) - but you need to make sure that the nesting option of the respective kvm kernel module is enabled:
https://pve.proxmox.com/wiki/Nested_Virtualization
 
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