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Proxmox

Install QEMU guest agent (Windows)​

  1. Mount the virtio-win.iso and install D:\guest-agent\qemu-ga-x86_64.msi
  2. Shutdown the system.
  3. On the Proxmox system, head to Options > QEMU Guest Agent > Use QEMU Guest Agent (tick the box)
  4. Power up the VM
  5. Open devmgmt.msc - look for PCI Simple Communications Controller and right-click it, then click Update Driver
  6. Select Browse my computer for drivers and feed it the path of D:\vioserial\YOUR-WINDOWS-VERSION\amd64\
  7. Per Proxmox docs, check if the service is running in PowerShell:
Get-Service QEMU-GA
  1. Additionally, from Proxmox command line you can run qm agent xxx ping to make sure an empty prompt is returned back (if you get QEMU guest agent is not running start at step 1 and double check everything).

Network connectivity issues for Linux VMs tagged with VLANs​

I had a super frustrating problem where after moving Linux VMs from one host to another, they weren't pulling DHCP or not able to route traffic or both. This post and ChatGPT nudged me towards making a /etc/netplan/01-netcfg.yaml file that looks something like this:

network:
  ethernets:
    ens18:
      dhcp4: true
    ens19:
      dhcp4: true
  version: 2

Once I did that and then sudo netplan apply the DHCP addresses got pulled and routing worked!

QM command cheat sheet​

Unlock a system (that might be locked from snapshot)​

qm unlock XXX

List machines​

qm list

Check status on if a particular machine is booted​

qm status xxx

Get full info on one VM - like if autoboot is set, hardware info, etc:​

qm config xxx

Enable autoboot (if onboot does not = 1 from `qm config X')​

qm set X -onboot 1

Change boot order​

qm set X --startup order=2,up=60

Stop a VM​

qm stop X

Take a snapshot​

qm snapshot xxx NAME-OF-SNAP --description

List snapshots​

qm listsnapshot xxx

Restore a snapshot​

qm rollback xxx NAME-OF-SNAP

Start a VM​

qm start X
qm set VMID -net0 virtio=THE:MAC:ADDRESS:OF:THE:PC,bridge=vmbr1,link_down=1,tag=10

Run a powershell command directly against a specific VM​

qm guest exec xxx -- cmd /c "dir c:\users\administrator\desktop"

Another example of downloading and then running a PowerShell script​

qm guest exec 100 -- cmd /c "powershell invoke-webrequest https://somesite/script.ps1 -outfile c:\users\administrator\desktop\script.ps1"
qm guest exec 100 -- cmd /c "powershell.exe -ExecutionPolicy Bypass -File "C:\\Users\\administrator\\Desktop\\script.ps1""

Yet another rexample of installing NIC driver on a fresh Windows build​

qm guest exec 100 -- cmd /c "pnputil /add-driver d:\NetKVM\w11\amd64\netkvm.inf /install"

Yet ANOTHER example of installing Chrome​

qm guest exec 100 -- cmd /c "powershell Invoke-WebRequest 'https://dl.google.com/chrome/install/chrome_installer.exe' -OutFile c:\users\ttadmin\desktop\chrome_installer.exe && c:\users\ttadmin\desktop\chrome_installer.exe /silent /install"

Then tailing the last 10 lines of a log file​

qm guest exec 100 -- cmd /c "powershell.exe -ExecutionPolicy Bypass -Command Get-Content -Path 'C:\\some\\path\\install.log' -Tail 10"

Check if qmagent is running​

qm agent xxx ping

Delete/destroy a VM​

qm destroy xxx

Backup a VM and move to another Proxmox node in a cluster​

vzdump <vmid> --storage <storage_name> --mode snapshot

Then move to another node:

scp /path/to/backup/vzdump-qemu-<vmid>.vma root@<destination_node_ip>:/var/lib/vz/dump/

Then restore:

qmrestore /var/lib/vz/dump/backup.vma <vmid> --storage <target-storage>

Example​

This will dump a snapshot of VM 121 to a file path like /var/lib/vz/dump/vzdump-qemu-121-2024_09_13-10_25_00.vma

vzdump 121 --storage local --mode snapshot

Now move to another node:

scp /var/lib/vz/dump/vzdump-qemu-121-2024_09_13-10_25_00.vma root@target.host.for.VM:/var/lib/vz/dump/

Now restore:

qmrestore /var/lib/vz/dump/vzdump-qemu-121-2024_09_13-10_25_00.vma 123 --storage local-lvm

In the example above, 123 is the VM ID you want to assign the imported host, and local-lvm is the storage pool to restore to.

Resize a disk​

Shutdown the affected VM, then check the details on the VM you want to resize:

qm config xxx

This will tell you what kind of hard drive type (like virtio0) you have

To do the resize and grow the disk by 20G:

qm resize 100 virtio0 +20G

Resize a disk at Linux command line​

Once the resizing is done, you can do the extending portion from the Linux command line. Using the latest Ubuntu OS as an example, here's what I did. First find the partion that needs growing:

sudo fdisk -l

Then grow it (in this example the target is dev/vda1:

sudo growpart /dev/vda 1

Finish the resizing:

sudo resize2fs /dev/vda1

Done!

Add memory (RAM) to a system​

For example, upgrade RAM to 8192:

qm stop (VMID)
qm set (VMID) -memory 8192
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