If you’re worried about destroying your SD Cards, need some more space, or just want to learn something new, I’m going to show you how to use an NFS root for the Raspberry Pi 4.
When you use an NFS Root with your Raspberry Pi, it stores the entire root filesystem on a remote NFS export (think of it as a network filesystem share). This means you’ll have as much space as the NFS export, and you’ll probably see way faster performance since it’ll be running at 1Gb/sec instead of the speed of the SD Card.
This also protects your SD card, as the majority of the reading and writing is performed on the physical storage of the NFS export, instead of the SD card in the Pi which has limited reads and writes.
What you’ll need
To get started, you’ll need:
Raspberry Pi 4
Ubuntu or Raspbian for Raspberry Pi 4 Image
A small SD card for the Boot Partition (1-2GB)
SD card for the Raspberry Pi Linux image
Access to another Linux system (workstation, or a Raspberry Pi)
There are multiple ways to do this, but I’m providing instructions on the easiest way it was for me to do this with the resources I had immediately available.
To boot your Raspberry Pi 4 from an NFS root, multiple steps are involved. Below you’ll find the summary, and further down you’ll find the full instructions. You can click on an item below to go directly to the section.
See below for the individual instructions for each step.
Write the Linux image to an SD Card
First, we need to write the SD Card Linux image to your SD card. You’ll need to know which device your SD card will appear to your computer. In my case it was /dev/sdb, make sure you verify the right device or you could damage your current Linux install.
Download Ubuntu or Raspbian for Raspberry Pi.
unzip or unxz depending on distribution to uncompress the image file.
Write the SD card image to SD card.
dd if=imagename.img of=/dev/sdb bs=4M
You now have an SD Card Linux install for your Raspberry Pi. We will later modify and then copy this to the NFS root and boot SD card.
Create boot SD Card for NFS Root
In this step, we’re going to create a bootable SD card that contains the Linux kernel and other needed files for the Raspberry Pi to boot.
This card will be installed in the Pi, load the kernel, and then kick off the boot process to load the NFS root.
After you do this, the Linux SD image may not boot again if directly installed in the Raspberry Pi, so make sure you’ve made the proper modifications before powering it down.
Create the NFS Export
In my case I used a Synology DS1813+ as an NFS server to host my Raspberry Pi NFS root images. But you can use any Linux server to host it.
If you’re using a synology disk station, create a shared folder, disable the recycling bin, leave everything else default. Head over to the “NFS Permissions” tab and create an ACL entry for your PI and workstations. You can also add a network segment for your entire network (ex. 192.168.0.0/24″) instead of specifying individual IPs.
Once you create an entry, it’ll look like this. Note the “Mount path” in the lower part of the window.
Now, if you’re using a standard Linux server the steps are different.
Install the require NFS packages:
apt install nfs-kernel-server
Create a directory, we’ll call it “nfs-export” on your root fs on the server:
Then create a directory for the Raspberry Pi NFS Root:
Now edit your /etc/exports file and add this line to the file to export the path:
Take note of the mount point and/or NFS export path, as this is the directory your Raspberry Pi will need to mount to access it’s NFS root. This is also the directory you will be copying your SD Card Linux install root FS to.
Copy the Linux install to the NFS Export
When you’re ready to copy your SD Card Linux install to your NFS Export, you’ll need to do the following. In my case I’ll be using an Ubuntu desktop computer to perform these steps.
When I insert the SD Card containing the Raspberry Pi Linux image, it appeared as /dev/sdb on my system. Please make sure you are using your proper device names to avoid using the wrong one to avoid writing or using the wrong disk.
Instructions to copy the root fs from the SD card to the NFS root export:
Mount the root partition of the SD Card Linux install to a directory. In my case I used directory called “old”.
mount /dev/sdb2 old/
Mount the NFS Export for the NFS Root to a directory. In my case I used a directory called “nfs”.
mount IPADDRESS:/nfs-export/PI-ImageName nfs/
Use the rsync command to transfer the SD card Linux install to the NFS Root Export.
In response to COVID 19, VMware has extended their VMware Horizon 7 trial offering up to 90 days and includes 100 users. This includes both VMware Horizon 7 On-Premise, as well as VMware Cloud on AWS.
This is great if you’re planning or about to implement and deploy VMware Horizon 7.
In it’s simplest form, Horizon 7 allows an organization to virtualize their end user computing. No more computers, no more desktops, only Zero clients and software clients. Not only does this streamline the end user computing experience, but it enables a beautiful remote access solution as well.
And Horizon isn’t limited to VDI… You can install the VMware Horizon Agent on a Physical PC so you can use VDI technologies like Blast Extreme to remote in to physical desktops at your office. It makes the perfect remote access solution. Give it a try today with an evaluation license!
In all my years assisting and providing support with VMware Horizon, one of the most common problems that customers report with their VDI implementations, is the VMware Horizon Blank Screen.
When a user is presented with a blank or black screen when using the VMware Horizon Client, the problem can be caused by a number of different things. In this post, I will address and provide solutions for some of the common issues that cause the VMware Horizon blank screen.
This troubleshooting guide applies to VMware Horizon 8, VMware Horizon 7, as well as earlier versions of VMware Horizon.
VMware Horizon Blank Screen Causes
There’s a number of different causes of a blank or black screen when connecting and establishing a VDI session to Horizon View. Click on the item below to jump to that section of the post:
Now that we have a list, let’s dive in to each of these individually. Some of these will require you to do your own research and will only guide you, while other sections will include the full fix for the issue.
VMware Tools and Horizon Agent Installation Order
When deploying the VMware Horizon View agent, you are required to install the agent, along with VMware tools in a specific order. Failing to do so can cause problems, including a blank screen screen.
The installation order:
Install GPU/vGPU drivers (if needed)
Install VMware Tools Agent
Install the VMware Horizon Agent
Install the VMware User Environment Manager Agent (if needed)
Install the VMware App Volumes Agent (if needed)
It is important to also consider this when upgrading the agents as well. When upgrading VMware Tools, it is recommended to re-install the Horizon agent in versions up to and including Horizon 8 2103. As of Horizon 2106 and later, you no longer need to re-install the Horizon Agent when performing a VMware Tools upgrade.
Certain types of IPS (Intrusion Prevention Service) can also intercept and block traffic. IPS may cause intermittent issues.
While VMware Horizon View usually uses IP address for connectivity between the View Connection Server, guest VM, and client, I have seen times where DNS issues have stopped certain components from functioning properly.
It’s always a good idea to verify that DNS is functioning both internally and externally. DNS (forward and reverse) is required for VMware Horizon Linux guests VMs.
XDR, EDR, and AV Platform causing momentary blank screen at logon
When using an XDR (Extended Detection and Response), EDR (Endpoint Detection and Response), or special AV solution with non-persistent desktops, one may experience a momentary blank screen on user session logon. I have observed this with Sophos XDR as well as Cortex XDR, with blank screens varying from 10-30 seconds on user login.
Removal of the platform can reduce the momentary blank screen down to 1-5 seconds.
I highly recommend configuring and tweaking policies as much as possible to enhance and optimize your environment. There will always be a trade off of performance for security, and the decisions should be made by those in the organization who make cyber security related decisions.
Incorrectly configured Unified Access Gateway
A big offender when it comes to blank screens is an incorrectly configured VMWare Unified Access Gateway for VMware Horizon.
Sometimes, first-time UAG users will incorrectly configure the View Connection server and UAG.
When configuring a UAG, you must disable both “Blast Secure Gateway”, and “PCoIP Secure Gateway” on the View Connection Server, as the UAG will be handling this. See below.
Another regular issue is when admins misconfigure the UAG itself. There are a number of key things that must be configured properly. These are the values that should be populated on the UAG under Horizon Settings.
Connection Server URL
Connection Server URL Thumbprint
sha1=SSLTHUMPRINT (Thumbprint of the SSL certificate your View Connection Server is using)
PCOIP External URL
Blast External URL
Tunnel External URL
You must also have a valid SSL certificate installed under “TLS Server Certificate Settings”. I’d recommend applying it to both the admin and internal interface. This is a certificate that must match the FQDN (internal and external) of your UAG appliance.
Once you’re good, you’re green!
You should always see green lights, all protocols should work, and the connections should run smooth. If not, troubleshoot.
GPU Driver Issue
When using a GPU with your VM for 3D graphics, make sure you adhere to the requirements of the GPU vendor, along with the VMware requirements.
Some vendors have display count, resolution, and other limits that when reached, cause Blast Extreme to fail.
An incorrectly installed driver can also cause issues. Make sure that there are no issues with the drivers in the “Device Manager”.
Make sure that if you are running 64-bit Windows in the VM then you install and use the 64-bit Horizon Agent.
You may experience issues with the “VMware Horizon Indirect Display Driver”. Some users have reported an error on this driver and issues loading it, resulting in a blank screen. To do this, I’d recommend forcibly uninstalling the driver and re-installing the Horizon Agent.
To forcibly remove the “VMware Horizon Indirect Display Driver”:
Open “Device Manager”
Right click on the “VMware Horizon Indirect Display Driver” and open “Properties”
On the “Driver” tab, select “Uninstall”
Check the box for “Delete the driver software for this device”.
Now proceed to uninstall and reinstall the Horizon View Agent.
When running the Horizon Agent on Horizon for Linux, make sure that forward and reverse DNS entries exist, and that DNS is functioning on the network where the Linux VM resides.
Also, as a reminder, it is recommended that you re-install the Horizon agent in versions up to and including Horizon 8 2103 after upgrading VMware Tools. As of Horizon 8 2106, you no longer need to re-install the Horizon Agent when performing a VMware Tools upgrade.
Video Settings (Video Memory (VRAM), Resolution, Number of Displays)
When experiencing video display issues or blank screens on VMware Horizon View, these could be associated with the guest VM’s memory, video memory (VRAM), display resolution, and number of displays.
If you do not have enough Video RAM (VRAM) allocated to the virtual machine and/or you have too many displays (multi-monitor), then you can experience the blank screen with Horizon.
Make sure you are adhering to the specifications put forth by VMware. Please see the following links for more information.
While this isn’t likely to cause a blank screen issue (it can though), it’s always a good idea to set your image to a lower resolution before snapping or converting to a template for deployment.
It’s a lot easier for the VMs to start using lower resolution and VRAM (Video Memory) and then increase to what’s needed, instead of starting at a crazy high resolution and then getting adjusted down.
I consider it a good practice to reduce the graphics resolution before creating and deploying the image to the desktop pools.
When troubleshooting blank screens with VMware Horizon, you need to try to identify whether it’s specific to the guest VM, or if it’s associated with the connection protocol you’re using (and the route it takes whether through a Connection Server, or UAG).
Always try different protocols to see if the issue is associated with all, or one. Then try establishing connections and find if it’s isolated direct to the Connection Server, or through the UAG.
If the issue is with a specific protocol, you can view the protocol log files. If the issue is with the UAG, you can troubleshoot the UAG.
Log files can be found in the following directory:
HTTPS Proxy and redirection issues
If you are connecting through a network that does passive and/or transparent HTTPS scanning or uses a proxy server, you may experience issues with inability to connect, or blank screens.
You’ll need to modify your firewall or proxy to allow the VMware connection and open the required ports for VMware Horizon and create an exception not to touch or manipulate the VMware Horizon related traffic.
Login banner or disclaimer (PCoIP)
I haven’t seen or heard of this one in some time, but when using VMware Horizon with PCoIP, sessions can fail or show a blank screen when the legal disclaimer login banner is used on the Windows instance (Windows 7, Windows 10, or Windows 11).
It never stops surprising me how old some of the VMware Horizon View environments are that some businesses are running. VMware regularly updates, and releases new versions of VMware Horizon that resolve known issues and bugs in the software.
While it may be difficult, simply upgrading your VMware Horizon environment (VMware vSphere, View Connection Server, VMware Tools, VMware Horizon Agent) can often resolve many issues.
Blank Screen connecting to Physical PC running Horizon Agent
After troubleshooting these issues, you should be able to resolve the issue.
As you can see there are a number of different things that can cause Horizon View to show a blank screen on login. It’s always best to try to understand how the technology works, and establish where the failure points are.
Let me know if this helped you out, or if you find other reasons and feel I should add them to the list!
This link will take you to sign up for a HPE iLO Advanced trial license. After filling out the form, you’ll be able to download your iLO welcome letter, which includes your iLO key (that is valid through 2020), and instructions.
This is awesome, and will definitely help out a ton of IT administrators this year to remotely manage, monitor, and maintain their servers.
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