Error 421 while connecting to Horizon via HTML Web Console after an upgrade to 2306 or Later

Hi, I experienced an issue where end users received an HTTP 421 error when connecting to a VMware Horizon web after it was upgraded to 2306. 

What is an HTTP 421 error?

The HTTP 421 Misdirected Request client error response code indicates that the request was directed to a server that is not able to produce a response. This might be possible if a connection is reused or if an alternative service is selected.


While connecting to Horizon over an HTML Web console, users encounter an error 421.


The default value of the security configuration setting allowUnexpectedHost has changed from true to false.

This means that connections using the name or IP address of a proxy, gateway, or load balancer that is not defined in will fail, even if checkOrigin and enableCORS are both set to false.


Add security configuration setting allowUnexpectedHost = true in your in connection servers after that restart Horizon services.

You can find from below address:

C:\Program Files\VMware\VMware View\Server\sslgateway\conf\

Finish 🙂

Increasing the disk space for the vCenter Server Appliance in vSphere 6.5, 6.7 and 7.0

Hi, Today I had a problem, my vCenter server storage/log was full.

I was able to solve it with these instructions:

To increase the disk space

  1. Power off the vCenter Server VM. If the VM is inaccessible, then do this from the ESXi host level
  2. Right-click the VM.
  3. Click Edit Settings.
  4. Select Virtual Disk.
  5. Increase the size of the disk. Ensuring there is no snapshot attached to VM. 
  6. Power on VM
  7. Use the BASH Shell or Appliance Management CLI o expand the partition(s).

Increase disk space using BASH Shell

  1. Log in to the vCenter Server Appliance using SSH and root credentials.
  2. Run this command to enable the Bash shell:

    shell.set –enabled true
  3. Type shell and press Enter.
  4. Use these commands to verify which disk is experiencing disk capacity issues, then trace which SCSI ID will show in the VM edit settings:
df -h;  lsblk;  lsscsi

5- Using the VAMI address –> https://vcenter:5480 –> Monitor –> Disks

You can find the Hard Disk number that you must be increased.

6- Using the vSphere Client or vSphere Web Client, locate the vCenter Server Appliance virtual machine and increase the disk space on the affected virtual disk.

7- After the virtual disk is increased, return to the SSH session and run this command to automatically expand any logical volumes for which the physical volumes are increased:


8- Run this command to confirm that the virtual disk has successfully grown:

df -h; lsblk; lsscsi

9- you can see it from VAMI

Finish 🙂


Today I updated my ESXi environemt, after that when i want migrate my VM’s from host”X” to host”Y”, I got this error:

“No guest OS heartbeats are being received error even when the VMware Tools service is correctly installed and is running on the guest VM”.

VMware knowledge base tells :

1- Ensure that the VMware Tools are installed in the virtual machine before performing a migration
2- Ensure that the virtual machine has been running long enough for the operating system to be completely started before performing a migration
3- If VMware Tools are already installed, reinstall the VMware Tools to ensure that you are on the latest version and that there is no corruption in the configuration.
4- However if VMware Tools is up and running when checking the vCenter and the VM, that’s all very well.
5- If you restart your vCenter server it can also trigger this behaviour!

There are two ways to fix this:

1- In your vSphere Client which is connected to your vCenter server, just open a Console window to the VM and then immediately close it again. You don’t even need to login to the VM!
2- Another way to correct this is to STOP and then RESTART the VMware Tools Service process on the VM.