vyos@r2-roll:~$ show int
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface        IP Address                        S/L  Description
---------        ----------                        ---  -----------
eth0             192.168.122.12/24                 u/u  
eth1             -                                 u/u  foo
lo               127.0.0.1/8                       u/u  
                 ::1/128                                
vyos@r2-roll:~$

vyos@r2-roll# show interfaces 
 ethernet eth0 {
     address 192.168.122.12/24
 }
 ethernet eth1 {
     description foo
 }
 ethernet eth2 {
     address 100.64.0.1/30
 }
[edit]
vyos@r2-roll#

vyos@r2-roll# delete interfaces ethernet eth2
[edit]
vyos@r2-roll# commit
[ interfaces ethernet eth2 ]
VyOS had an issue completing a command.

We are sorry that you encountered a problem while using VyOS.
There are a few things you can do to help us (and yourself):
- Make sure you are running the latest version of the code available at
  https://downloads.vyos.io/rolling/current/amd64/vyos-rolling-latest.iso
- Consult the forum to see how to handle this issue
  https://forum.vyos.io
- Join our community on slack where our users exchange help and advice
  https://vyos.slack.com

When reporting problems, please include as much information as possible:
- do not obfuscate any data (feel free to contact us privately if your 
  business policy requires it)
- and include all the information presented below

Report Time:      2020-08-10 21:01:14
Image Version:    VyOS 1.3-rolling-202008101519
Release Train:    equuleus

Built by:         [email protected]
Built on:         Mon 10 Aug 2020 15:19 UTC
Build UUID:       1559e709-8201-423c-a839-bc640e610f45
Build Commit ID:  99114c57bad638

Architecture:     x86_64
Boot via:         installed image
System type:      KVM guest

Hardware vendor:  QEMU
Hardware model:   Standard PC (Q35 + ICH9, 2009)
Hardware S/N:     
Hardware UUID:    707134eb-893f-4c31-97e2-8c3c1f8b702b

Traceback (most recent call last):
  File "/usr/libexec/vyos/conf_mode/interfaces-ethernet.py", line 86, in <module>
    apply(c)
  File "/usr/libexec/vyos/conf_mode/interfaces-ethernet.py", line 73, in apply
    e = EthernetIf(ethernet['ifname'])
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 237, in __init__
    self._create()
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 251, in _create
    self._cmd(cmd)
  File "/usr/lib/python3/dist-packages/vyos/ifconfig/control.py", line 51, in _cmd
    return cmd(command, self.debug)
  File "/usr/lib/python3/dist-packages/vyos/util.py", line 179, in cmd
    raise OSError(code, feedback)
FileNotFoundError: [Errno 2] failed to run command: ip link add dev eth2 type ethernet
returned: 
exit code: 2

noteworthy:
cmd 'ip link add dev eth2 type ethernet'
returned (out):

returned (err):
RTNETLINK answers: Operation not supported

delete [ interfaces ethernet eth2 ] failed
Commit failed
[edit]
vyos@r2-roll#

vyos@r2-roll# sudo lspci | grep -i eth
01:00.0 Ethernet controller: Red Hat, Inc Virtio network device (rev 01)
02:00.0 Ethernet controller: Red Hat, Inc Virtio network device (rev 01)
[edit]
vyos@r2-roll#