Managing a Proxmox Host

In my last post we went over installing a Proxymox host and we did a fair bit of managing already… ok mostly just storage but we had to manage the host after the initial install of the base OS. This should be pretty obvious, it’s a web interface, which is stated right on the Console output after you install. All the commands in the previous blog could have all been done from the direct system console, but also via remote SSH.

So, first act is to change the update repo, by removing the enterprise ones and adding the no-sub repo for updates. This alone won’t resolve the nagging pop up when you log in about having no subscription. to get rid of that:

Remove the annoying subscription pop-up

  1. Open the Shell terminal from your Proxmox web UI or connect via SSH as root.
  2. Navigate to the widget toolkit directory:
    cd /usr/share/javascript/proxmox-widget-toolkit/

    Make a backup copy of proxmoxlib.js:

    cp proxmoxlib.js proxmoxlib.js.bak
    
  3. Open the file in a text editor like nano:
    nano proxmoxlib.js
    
  4. Search for the text active (press Ctrl + W in nano).
  5. Locate the conditional check that looks for an active status, which typically contains !== 'active' or !res logic. Change the inequality exclamation mark ! to make it an equality check == 'active' (removing the ! so it evaluates positively instead of triggering the warning when inactive). Alternatively, comment out or bypass the function call according to your specific Proxmox minor version.
  6. Save the file (Ctrl + O, then Enter) and exit (Ctrl + X).
  7. Restart the Proxmox proxy service to apply the change:
    systemctl restart pveproxy.service
    
  8. Perform a hard refresh or clear your browser cache (Ctrl + F5)

System Resources

I basically just click on the host summary tab. or a VMs summary tab.

Or install “glances” on the terminal shell.

Networking

I know, I know, you’re probably screaming about authentication and user management, groups, permissions. probably yelling “RBAC!!” I’m gonna stick to using root for now and concentrate on infrastructure stuff for now.

When configuring Proxmox in a multi-subnet or VLAN environment, you quickly run into the limitations of the Linux kernel’s “Weak Host Model,” which handles routing very differently than enterprise firewalls like Palo Alto Networks (PAN-OS). Unlike zone-based firewalls that use policy-based forwarding to automatically reply out of the same interface a packet arrived on, Linux relies strictly on destination-based routing tables. This becomes a major trap if you assign identical or overlapping subnets to multiple network interfaces; even if you physically unplug a network cable, the Linux kernel holds onto that dead route at the top of its table. This causes traffic to be shoved down a disconnected interface, resulting in frustrating “No Route to Host” errors and dropped connections, even when your other live interface is perfectly configured.

Furthermore, setting up multi-homed access to the Proxmox Web UI introduces asymmetric routing challenges, as Linux only permits a single global default gateway by default. If traffic arrives on a secondary VLAN interface, Proxmox will mistakenly attempt to send the reply back out the primary management gateway, causing firewalls to log “aged out” or “incomplete” states due to the routing mismatch. To resolve this, administrators must either use the CLI to inject custom policy-based routing rules (ip rule and separate routing tables) into the network configuration file or cleanly isolate their subnets by stripping duplicate IP layers off disconnected bridges. Additionally, when testing these secondary access points, remember that the Proxmox web service strictly binds to its local hosts configuration and requires explicit HTTPS formatting over port 8006 (https://<IP>:8006) to successfully initialize a session.

That’s a long winded way to say that when I was trying to keep the flat home network (untagged) ip address on the Proxmox server, while also giving it a virtual interface attached to another VLAN tagged subnet. It wouldn’t connect (or it wouldn’t load) the web interface from my home untagged network, even though it was routed, and tagged properly on all network devices along the network path.

So from what I can tell:

a “Linux Bridge” is like a vmware vSwitch. You define the physical connection the host has to these bridges.

a “Linux VLAN” is like a VMK. This is where you define another IP address the host can use. You select which device by defining VLAN raw device, which seem you can pic the physical NIC or the bridge, I don’t know the implication if you pic the nic when its already configured for a bridge though… I’m still learning here.

When you edit a VMs NIC settings you pick a bridge, and you can define what vlan the traffic will be at the VMs NIC settings, this is like the VMPG on ESXi.

Did I break updates from this… yup looks like it.. DNS works.. but can’t reach out anywhere or yeah.. locked down subnet, that was easily fixed.

Edited a VM NIC settings, change bridge, added VLAN Tag. Disconnect, power on VM, apply static IP, change to connect, yup.. works just fine.

Interacting with VMs

Virt-Viewer and Virt-Manager

PVE has the web console built right in, so you can just manage the VM directly that way. I like being able to have an app window for the connection much like VMRC for VMware. Which PVE has, called Virt-viewer, get it here: Virtual Machine Manager. I installed the Winx64 binaries.

One trick I like to do is connect a USB stick to my main mgmt machine, then copy files to it, then to a VM if I need to get files on to said VM if the VM is an offline only machine.

Since I deployed this VM from a generalized image I had created I needed to pick a storage controller that I knew would be natively available to the image I was using so I stuck with the LSI, I installed virt-viewer so SPICE as my GPU, and again a native supported NIC, so the E1000.

As you can also see, they are all generic drivers, but.. working:

So as you see, not terrible, but also not crazy, I know those 3 SSDs can perform better then these results since I did an I/O test on them via the host backend, so I’m assuming I have so loss in the virtual bus controller (the LSI 53C) or the standard Windows drivers. So, the first thing I want to test is installed the guest tools, will they change how devices show in the device manger, and will there be any performance increases?

Spice Guest Tools

So downloaded them on the guest VM from “www.spice-space.org/download.html”

not sure what was up with the serial driver, but I just accepted it:

Well…

Windows Main Device? No USB Trick for you!

  1. Even after all that, the video drivers showed up without basic drivers, and I can move in and out of the VM in the virt-viewer with having to press CTRL+ALT+R. That’s Good.
  2.  The Storage device in device manager still shows generic SATA ACHI so I don’t believe I’ll get any better I/O results.
  3. Attempting to add a SPICE USB port to the VM hardware worked but…

after shutting down the VM and power it back on, the device list wasn’t greyed out and showed one free channel. but picking any of my devices…

ok… this might be cause my mgmt machine is Windows?

I want to like PVE, but there are a lot of little niche things that are pissing me off about it. Then when you want to use SPICE with virt-viewer, it downloads a spice.vv file that you have to open, which auto deletes when the VM is shutdown or close (haven’t tested this). just feels like weird UX. anyway…

Storage Controller vs Virtual Hard Drives

I changed the SCSI controller from LSI 53C to VirtIO SCSI Single. But when I booted the VM back up I still saw the same generic SATA ACHI Controller. I felt like there was some ignorance on my part so I asked AI for any insights, it informed me to add a drive cause the type on the actual virtual disk could still be bound to the old type. So I temp added a disk (just for testing) and changed the connection from SATA to SCSI and checked the dev mgmt and ran a test and the performance was a fair bit better…

compared to

Performance Increase Overview

Benchmark Test Metric Type Performance Change Percentage Increase
Seq1M-Q8T1 Read 433 MB/s → 651 MB/s +50.3%
Write 56 MB/s → 95 MB/s +69.6%
Seq1M-Q1T1 Read 400 MB/s → 511 MB/s +27.8%
Write 51 MB/s → 54 MB/s +5.9%
Ran4K-Q32T1 Read 14 MB/s → 136 MB/s +871.4%
Write 7 MB/s → 7 MB/s 0.0% (No Change)
Ran4K-Q1T1 Read 6 MB/s → 13 MB/s +116.7%
Write 1.5 MB/s → 2 MB/s +33.3%

Key Takeaways
  • Massive Random Read Improvement: The biggest leap is in Ran4K-Q32T1 Read, sky-rocketing by 871.4%. This means heavy multi-threaded background random tasks will feel exponentially faster.
  • Solid Sequential Gains: Large file transfers (Seq1M) see a great bump, with reads improving by roughly 28% to 50%, and multi-queued writes jumping by nearly 70%.
  • Lagging Write Speeds: Random deep-queue writes (Ran4K-Q32T1) didn’t improve at all, and sequential single-thread writes (Seq1M-Q1T1) only crawled up by 5.9%.

That’s a bit improvment, I need to get the base OS HDD on this new type to gain the performance increase. Do to that:

Swap the Real Drive to SCSI

  1. In the Proxmox Hardware tab, select the 1 GB dummy disk you just made and click Detach. Then select the detached unused disk and click Remove.
  2. Select your main Windows boot disk (currently sitting on sata0 or ide0) and click Detach. It will immediately drop down to the bottom of the hardware list as an Unused Disk 0.
  3. Double-click that Unused Disk 0.  (I don’t know why double click seemed the only option I couldn’t see any action items at the top)
  4. In the pop-up window, change the Bus/Device dropdown to SCSI (it will likely assign scsi0). Click Add.

Fix the Boot Order

  1. Go to the VM’s Options tab in Proxmox.
  2. Double-click Boot Order.
  3. Check the box for your newly reattached scsi0 drive and drag/button it to the very top of the list so it is the primary boot device. Click OK.

Yeah for some reason it wasn’t checked off, so reattaching a vHDD has this implication something I didn’t instinctively had to do, in the snip above I unchecked net boot and checked off the scsi0.

Start your VM. before I ran the test I wanted to make sure the baseline VM was fine for it since now it was the Windows main OS drive that was running on the new virtual SCSI bus. however sure enough windows updates were alerady hitting the disk and the CPU.. I noticed it in task a manager, which was also showing me…
like what?! 84% active time constant, with a contant 800+ ms repsonse time and a measly 1.7MB/s … is windows doing insane I/o and bottle necking the I/O bus? was the theory all BS, or would this have happened on the settings I had before…? So many questions, so little answers… but the results are not good the Windows updates process is low CPU and high wait time on disk it seems the disk is slowing things down….
well system is back to idle windows updates completed.. lets see what diskmark has to say… shows the same results as “D:\” so we should have got the I/O performance increase, yet.. I remain skeptical….

Summary

So, we touched a bit on some basic management of a Proxmox host, like checking system resources, networking, storage, and managing VMs. Each of these are not covered in depth by any means, but just the simple fundamentals to getting a VM up and running and basic management of them.
These fundamentals are needed for the next stage, migrating VMs from ESXi to ProxMox. I know, I know, you’re saying I already did a basic pilot of that in the past here: Migrate ESXi VM to Proxmox – Zewwy’s Info Tech Talks but that was a bare metal, bare FS and using a linux VM with a convertion tool to just convert the  base HDD and it’s associated FS intact the version required by the hypervisor. It also took a lot of space, bandwidth, I didn’t explain what each step was really doing in detail. Anyway, long story short in the next blog post I’m gonna see how we can use Veeam to do a migration instead of a linux machine.

Migrate ESXi VM to Proxmox

I’m going to simulate migrating to Proxmox VE in my home lab.

I saw this YT video comparing the two and gave me the urge to try it out in my home lab.

In this test I’ll take one host from my cluster and migrate it to use Proxmox.

Step one, move all VMs off target host.
Step two, remove host from cluster.
Step three, shutdown host.

In this case it’s an old HP Folio laptop. Next Install PVE.

Step one Download Installer.
Step two, Burn image or flash USB stick with image.
Step 3 boot laptop into PVE installer.

I didn’t have a network cable plugged in, and in my haste I didn’t pay attention to the bridge main physical adapter, it was selected as wlo1 the wireless adapter. I found references to the bridge info being in /etc/network/interfaces some reason this was only able to get pings to work. all other ports and services seemed completely unavailable.  Much like this person, I simply did a reinstall (this time minding the physical port on network config). Then got it working.

First issue I had was it poping up saying Error Code 100 on apt-get update.

Using the built in shell feature was pretty nice, use it to follow this to change the sources to use no-subscription repos.

The next question was, how can I setup another IP thats vlan tagged.

I thought I had it when I created a “Linux VLAN”, and defining it an IP within that subnet and tagging the VLAN ID. I was able to get ping replies, even from my machine in a different subnet, I couldn’t define the gateway since it stated it was defined on the bridge, make sense for a single stack. I figured it was cause ICMP is UDP and doesn’t rely on same paths (session handshakes) and this was probably why the web interface was not loading. I verified this by connecting a different machine into the same subnet and it loaded the web interface find, further validating my assumptions.

However when I removed the gateway from the bridge and provided the correct gateway for the VLAN subnet I defined, the wen interface still wasn’t loading from my alternative subnetting machine. Checking the shell in the web interface I see it lost connectivity to anything outside it’s network ( I guess the gateway change didn’t apply properly) or some other ignorance on my part on how Proxmox works.

I guess I’ll leave the more advanced networking for later. (I don’t get why all other hypervisors get this part so wrong/hard, when VMware makes it so easy, it’s a checkbox and you simply define the VLAN ID in, it’s not hard…) Anyway I simply reverted the gateway back to the bridge. Can figure that out later.

So how to convert a VM to run on ProxMox?

Option 1) Manually convert from VMDK to QCOW2

or

Option 2) Convert to OVF and deploy that.

In both options it seems you need a mid point to store the data. In option 1 you need to use local storage on a Linux VM, almost twice it seems once to hold the VMDK, and then enough space to also hold the QCOW2 converted file. In option 2 the OP used an external drive source to hold the converted OVF file on before using that to deploy the OVF to a ProxMox host.

I decided to try option 1. So I spun up a Linux machine on my gaming rig (Since I still have Workstation and lots of RAM and a spindle drive with lots of storage). I picked Fedora Workstation, and installed openssh-server, then (after a while, realizing to open firewall out on the ESXi server for ssh), transferred the vmdk to the fedora VM:

106 MB/s not bad…

Then installed the tools on the fedora VM:

yum install -y qemu-img

NM it was already installed and converted it…

On Proxmox I couldn’t figure out where the VM files where located “lvm-thin” by default install. I found this thread and did the same steps to get a path available on the PVE host itself. Then used scp to copy the file to the PVE server.

After copying the file to the PVE server, ran the commands to create the VM and attach the hdd.

After which I tried booting the VM and it wouldn’t catch the disk and failed to boot, then I switched the disk type from SCSI to SATA, but then the VM would boot and then blue screen, even after configuring safe mode boot. I found my answer here: Unable to get windows to boot without bluescreen | Proxmox Support Forum

“Thank you, switching the SCSI Controller to LSI 53C895A from VirtIO SCSI and the bus on the disk to IDE got it to boot”.

I also used this moment to uninstall VMware tools.

Then I had no network, and realized I needed the VirtIO drivers.

If you try to run the installer it will say needs Win 8 or higher, but as pvgoran stated “I see. I wasn’t even aware there was an installer to begin with, I just used the device manager.”

That took longer then I wanted and took a lot of data space too, so not an efficient method, but it works.

ESXi VM disconnected after applying patch

Keep this short.

I had to update a ESXi host locally as it’s mgmt connection would drop with all VMs having to go down on it. As it’s a single host with virtualized network components.

On one of the VMs this was an opportunity to update it since it needed to be shutdown temperately anyway. I took a snapshot of the VM, updated it, validated updates were fine, removed the snapshot. Then proceeded to update the host:

vim-cmd hostsvc/Maintenance_mode_enter
esxcli software vib update -d "/path/to/file.zip"
vim-cmd hostsvc/Maintenance_mode_exit
reboot

Nothing special here. However once the host came back up and I was able to access it via vCenter, one of the VM’s was shown as “disconnected” I’ve seen this with ESXi hosts before, but not particularly with a VM.

Oddly enough there’s only one datastore on the host and all other VMs are fine, and checking the datastore, all files are where they should be.

I figured maybe remove the VM from inventory and just re-add it via the vmx file, however the option was greyed out.

It turned out there was apparently still a snapshot left on the VM (noticed via delta files existing within the VMs folder path).

Removing all the snapshots resolved the issue. Turns out the VM was also running, but didn’t show the green play icon, thus I wasn’t aware of it’s powered on state. Which also explains the greyed out context menu for removing from inventory.

Hope this helps someone.