Category: Virtualization

How to Delete a Virtual Machine in Proxmox
Here is what you need to do to delete a VM in proxmox.

1) log in to Proxmox.

2) Find the VM you need to delete.

3) Shutdown the VM

When it asks for confirmation, press “Yes”

4) After VM is stopped, click on the “More” button. You will see the option to remove the Virtual machine.

It will ask for deletion confirmation. You must enter VM ID and click the “Remove” button to delete the virtual machine.

Delete a VM using command line

First, stop the Virtual machine
```
qm stop VM_ID
```
Then delete the VM with
```
qm destroy VM_ID
```
Back to Proxmox
November 24, 2022

How to delete KVM Virtual machine using virsh

Deleting a KVM virtual machine using “virsh” is a multi-step process. You need to stop the virtual machine, find the storage device used by them VM, and remove the storage devices. Then undefine the virtual machine.

Here are the commands used to delete a KVM VM with the name win10.

First shutdown the VM

virsh shutdown win10

If it did not stop, you can force stop with the command

virsh destroy win10

Find information about the VM with the command “virsh dumpxml –domain VM_NAME”

root@mail:~# virsh dumpxml --domain win10

  win10
  e40399f7-9936-41ce-9a70-0251cb948cae
  
    
      
    
  
  16777216
  16777216
  4
  
    hvm
    
  
  
    
    
    
      
      
      
    
    
  
  
  
    
    
    
    
  
  destroy
  restart
  destroy
  
    
    
  
  
    /usr/bin/qemu-system-x86_64

In the above result, you can see we are using the following storage device for this VM

This VM uses the storage device /dev/vg1/win10, we need to remove it.

lvremove /dev/vg1/win10

The VM also uses ISO file /var/lib/libvirt/images/Win10_21H2_English_x64.iso, if you don’t need it, you can delete it.

rm -f /var/lib/libvirt/images/Win10_21H2_English_x64.iso

To delete the VM, you can use

virsh undefine win10

Example

root@mail:~# virsh undefine win10
Domain win10 has been undefined

root@mail:~#

Back to virsh

November 21, 2022

How to force shutdown a KVM VM with virsh

I have a KVM virtual machine running Windows, and when I try to shutdown, it never stopped.

root@sok:~# virsh list
 Id   Name       State
--------------------------
 1    iredmail   running
 3    win10      running

root@sok:~# virsh shutdown win10
Domain win10 is being shutdown

root@sok:~# virsh list
 Id   Name       State
--------------------------
 1    iredmail   running
 3    win10      running

root@sok:~#

To force shutdown a KVM virtual machine using virsh, you can use the command

virsh destroy VM_NAME

Example

root@sok:~# virsh destroy win10
Domain win10 destroyed

root@sok:~# virsh list 
 Id   Name       State
--------------------------
 1    iredmail   running

root@sok:~# virsh start win10
Domain win10 started

root@sok:~# virsh list
 Id   Name       State
--------------------------
 1    iredmail   running
 4    win10      running

root@sok:~#

Back to virsh

November 21, 2022

Vultr

How to Reinstall Operating System on Vultr VPS

February 14, 2022

Configure KVM Bridge Network using netplan

On Ubuntu 20.04 server we have the following network configuration

root@mail:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: enp2s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether d8:cb:8a:e3:c7:c9 brd ff:ff:ff:ff:ff:ff
    inet 37.157.249.137/32 scope global enp2s0
       valid_lft forever preferred_lft forever
    inet6 fe80::dacb:8aff:fee3:c7c9/64 scope link 
       valid_lft forever preferred_lft forever
root@mail:~#

“netplan get all” command show following

netplan config file has the following

root@mail:~# cat /etc/netplan/01-netcfg.yaml 
# This file describes the network interfaces available on your system
# For more information, see netplan(5).
network:
  version: 2
  renderer: networkd
  ethernets:
    enp2s0:
      addresses: [ 37.157.249.137/32 ]
      nameservers:
          search: [ venus.dedi.server-hosting.expert ]
          addresses:
              - "8.8.8.8"
              - "1.1.1.1"
      routes:
      - to: 0.0.0.0/0
        via: 37.157.249.129
        on-link: true

root@mail:~#

Before you can use bridge in netplan, you need to install bridge-utils

apt-get install bridge-utils

To configure bridge networking, modify the file as follows

network:
    version: 2
    renderer: networkd
    ethernets:
        enp2s0:
            dhcp4: no
            dhcp6: no
    bridges:
        br0:
            dhcp4: no
            dhcp6: no
            interfaces: [enp2s0]
            addresses: [ 37.157.249.137/32 ]
            nameservers:
                addresses:
                    - "8.8.8.8"
                    - "1.1.1.1"
            routes:
            -   to: 0.0.0.0/0
                via: 37.157.249.129
                on-link: true

To check if there is any error in netplan configuration, run

netplan generate

To test the configuration, run

netplan try

Here is an example https://gist.github.com/serverok/712b85432d188f16c9d32e44455b419a

Back to netplan

February 10, 2022

Proxmox LXC container docker not working

On a Proxmox server, LXC container failed to run docker. When I start a docker container, I get the following errors.

root@erpdo:~# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
2db29710123e: Pull complete 
Digest: sha256:2498fce14358aa50ead0cc6c19990fc6ff866ce72aeb5546e1d59caac3d0d60f
Status: Downloaded newer image for hello-world:latest
docker: Error response from daemon: failed to create shim: OCI runtime create failed: container_linux.go:380: starting container process caused: process_linux.go:545: container init caused: rootfs_linux.go:76: mounting "proc" to rootfs at "/proc" caused: mount through procfd: permission denied: unknown.
root@erpdo:~#

To fix the error, in proxmox, click on the container, then go to Options.

Proxmox > Container Name > Options > Features

Click on Features, then click edit. You will see a popup like

On this screen, enable the following 2 options

keyctl
Nesting

Stop and start the container. After this, the docker container will work inside the LXC container in proxmox server.

December 26, 2021

Migrate physical server to LXD container
lxd-p2c is developed by LXD team to migrate physical servers into LXD containers.

https://github.com/lxc/lxd/tree/master/lxd-p2c

Static binary files are available in Github. To Download, go to

https://github.com/lxc/lxd/actions

Click on any of the actions with a green tick mark. Under Artifacts, you will see the download link for various operating systems.

Download the Linux.zip file, extract, copy the “lxd-p2c” file to the physical server that you need to convert to LXD container.

Before migrating

You need to stop all services like web server, MySQL server, etc before you run lxd-p2c migration.

Running lxd-p2c

Before you can run the migration, you need to create an LXD container with the same OS as the physical server.

Then run the following command on the physical server to migrate files to the LXD container you created.
```
./lxd-p2c https://lxdserver:8443 NEW_CONTAINTER_NAME /
```
It is will ask for LXD password, if you don’t have it, use the following command to reset the password on the LXD server.
```
lxc config set core.trust_password PASSOWORD_HERE
```
December 23, 2021
Static IP for CentOS LXC container
LXC containers get dynamic IP from DHCP. When you stop and start a container, its IP gets changed. If you hosting some web application on this container, you need to point the application to new IP. To avoid this, you can configure static IP on the container.

LXC containers get IP in the range 10.0.3.2-255. To make CentOS container IP static, edit file
```
vi /etc/sysconfig/network-scripts/ifcfg-eth0 
```
Find
```
BOOTPROTO=dhcp
```
Replace with
```
BOOTPROTO=STATIC
```
Add below
```
IPADDR=10.0.3.2
GATEWAY=10.0.3.1
DNS1=1.1.1.1
DNS1=8.8.8.8
```
10.0.3.2 = replace with any unused IP in the range your LXC container assign using DHCP.

Create a static route file
```
vi /etc/sysconfig/network-scripts/route-eth0
```
Add
```
10.0.3.1 dev eth0
default via 10.0.3.1 dev eth0
```
After restarting the LXC container, you will have a fixed IP.
```
reboot
```
December 13, 2021
Where LXC Container files are stored?
LXC containers are stored in folder /var/lib/lxc

Each container have a folder, which contains
```
/var/lib/lxc/VM_NAME_HERE/config = configuration file
/var/lib/lxc/VM_NAME_HERE/rootfs = file system used by lxc container.
```
LXC container OS templates are stored in
```
/usr/share/lxc/templates
```
See LXC
December 2, 2021
LXC container networking not working
On a Debian server, I installed lxc, but when I create a container, it is missing IP address. When I did “lxc-attack VM_NAME”, and checked the network interface with “ip link” command, i can only see the loopback interface “lo”.

On Host machine, when I checked network interfaces, lxcbr0 was missing. To fix this, edit file
```
vi /etc/default/lxc 
```
Find
```
USE_LXC_BRIDGE="false"
```
Replace with
```
USE_LXC_BRIDGE="true"
```
Now restart lxc-net service
```
systemctl restart lxc-net
```
At this point, you will see the network interface “lxcbr0”.
```
root@b24:~# brctl show
bridge name	bridge id		STP enabled	interfaces
br-52702762660a		8000.024201845e4b	no		
docker0		8000.0242ee9122d8	no		
lxcbr0		8000.00163e000000	no		vethDED0EK
lxdbr0		8000.00163e7d81a2	no		
root@b24:~#
```
Next edit file
```
vi /etc/lxc/default.conf
```
I had the following content in this file

root@b24:/etc/lxc# cat default.conf
lxc.net.0.type = empty
lxc.apparmor.profile = generated
lxc.apparmor.allow_nesting = 1
root@b24:/etc/lxc#

Find
```
lxc.net.0.type = empty
```
Replace with
```
lxc.net.0.type = veth
lxc.net.0.link = lxcbr0
lxc.net.0.flags = up
```
After this is done, newly created LXC containers get IP addresses.
```
root@b24:~# lxc-ls -f
NAME STATE   AUTOSTART GROUPS IPV4       IPV6 UNPRIVILEGED 
vm-1 RUNNING 0         -      10.0.3.128 -    false        
root@b24:~# 
```
See LXC
December 2, 2021

lxc storage list

To list Storage in LXD, use the command

lxc storage list

Example

root@b24:~# lxc storage list
+---------+--------+--------------------------------------------+-------------+---------+
|  NAME   | DRIVER |                   SOURCE                   | DESCRIPTION | USED BY |
+---------+--------+--------------------------------------------+-------------+---------+
| default | btrfs  | /var/snap/lxd/common/lxd/disks/default.img |             | 7       |
+---------+--------+--------------------------------------------+-------------+---------+
root@b24:~#

In this installation, we use btrfs file system for storing containers. The file location is /var/snap/lxd/common/lxd/disks/default.img. It is used by 7 containers.

See LXD

July 17, 2021

How to know you are inside a LXD container?
You have access to a virtual machine, you need to find out what virtualization technology it uses, you can install virt-what
```
apt instal virt-what
```
Then run virt-what command, it will show what virtualization technology you are using.
```
root@mysql-1:~# virt-what
lxc
root@mysql-1:~#
```
Another way to find is using the command. If you use LXD container, you will see the following files/directories.
```
root@mysql-1:~# ls -la /dev | grep lx
-r--r--r-- 1 root   root          37 Jun 30 21:15 .lxc-boot-id
drwx--x--x 2 nobody nogroup       40 Jun 30 21:15 .lxd-mounts
drwxr-xr-x 2 nobody nogroup       60 Jul 12 17:13 lxd
root@mysql-1:~# 
```
Also mount command will show many lxcfs mounts.

See LXD
July 16, 2021

Category: Virtualization

Delete a VM using command line

Before migrating

Running lxd-p2c