June 3, 2024

Hosts out of sync after restoring vCenter


After working with VMware Support on a case we were asked to install a special patch on the vCenter server. It turned out this patch broke some unrelated functionality we needed (remounting rdm disks on a VM that already had 35 rdm disks). This script runs at night and the next day we decided to roll back vCenter to the backup from the previous day; to the backup that was taken just before the patch was installed.


Some of our ESXi hosts started showing symptoms of being out of sync, all the stats became blank and no alarms were triggered, just two blue info messages. Trying to reconfigure HA would however trigger alarms. 

Cannot synchronize host servername
Quick stats on servername is not up-to-date

Quick stats on xxxx is not up-to-date

The password for the vpxuser changes every 30 days and with many hosts in your vCenter it can potentially affect quite a few hosts depending on the time frame between the backup and the rollback. VMware has a list of things to consider when doing a restore, but the problem we experienced is not on the list.  

When you have 150 esxi hosts in your vCenter it can be time consuming to manually go through each host to find which hosts have been affected by the rollback.
Get-AdvancedSetting -Entity ($DefaultVIServer).Name -Name VirtualCenter.VimPasswordExpirationInDays
Get-AdvancedSetting -Entity ($DefaultVIServer).Name -Name VirtualCenter.VimPasswordExpirationInDays

Searching through the logs of one of the affected hosts revealed little about that it was having problems.


By looking at the logs through Splunk we could find a log entry from vCenter that blew up after the restore:

Exception occurred during host sync; Got method fault

Now we could use Splunk to give us a list of the affected servers.

Then we could right click each server from the vSphere client and chose Disconnect and then Connect again.

Disconnect + Connect

After having reconnected the hosts things were working fine again and the ongoing error messages we had in Splunk stopped coming.

December 28, 2023

Jumpstart plugin late-filesystem activation failed


When installing ESXi you sometimes get this error message after pressing F11 to accept the EULA:


The reason you're seeing this problem is because your Alt button has magically stuck within your iDRAC/iLO/RSA session and you're seeing tty11 instead of tty2. Pressing alt+F2 bring you back to the EULA page again. Press Alt by itself once and then F11 will allow you to continue the installer.

April 1, 2023

CloudBuilder fails to deploy vCenter during initial deployment

When deploying VCF 4.5 you should be able to do that in an air gapped environment that has no access to the internet. In such cases you will need to get updates and such into the environment manually, but it's still a supported solution.

When running the initial bring up process deployment will fail with the message: "vCenter installation failed. Check logs for more details.". The vcf-bringup.log file will tell you that the vCenter appliance was deployed and started, but that there's was problem with the time of this appliance. 

The ntp parameters you have specified in your spreadsheet have been populated correctly in /etc/ntp.conf of the Cloud Builder appliance, but the logs show that it's trying to connect to the Google ntp servers.


The only solution we've found so far is to either impersonate Google's ntp entries in dns or to open the firewall and let Cloud Builder communicate with these external servers. Cloud Builder is only used during bring up so these workarounds can be reverted once the environment is up and running. 

March 1, 2023

LPe12000 and other old Emulex cards are unsupported if you patch ESXi 7.0U3


In January 2020 Broadcom announced that a series of Emulex cards would soon go End Of Life. They have however worked fine in VMware ESXi until recently, including 7.0U3d. 


If you patch your ESXi 7 host with the latest patches the lpfc driver will be replaced by one that doesn't support these old cards and you will no longer see your FC LUNs (vmfs datastores & RDM disks). The driver will be upgraded from to 14.0.543.0. We've also found that installing ESXi 7.0U3j comes with a non-working driver.


Using supported hardware is always recommended. Swapping these old cards with newer ones would be optimal.


Installing an old driver (right click this link, Save As) that still supports old hardware is possible and you will then see your LUNs again.


In order to identify where this problem will occur before patching I used the following PowerCLI script:

$vmhosts = get-vmhost|sort-object

foreach($vmhost in $vmhosts){

  $devices = Get-VMHostHba -VMHost $vmhost.Name | Where-Object {$_.Model -match "3530C|LPe1605|LPe12004|LPe12000|LPe12002|SN1000E"}

  foreach ($device in $devices) {

    Write-Output "$vmhost - $($device.Model) device with WWN $($device.PortWorldWideName)"



This script will check the HBAs of all of your ESXi hosts and you'll get a listing similar to this:

It's highly unusual that a device gets unsupported while patching a version of ESXi. As far as I can recall we have only seen devices being discontinued between major or minor versions of ESXi, not while installing non-critical patches.

May 4, 2022

Horizon Client 8.5 crashing on Linux


After upgrading from version 8.4 the Horizon Client was unable launch correctly. Launching it from the command line showed a segmentation fault:

I'm using Ubuntu 20.04 LTS, but other related distros may also be affected.


It turned out that Reddit user Zixyar had already found that you could solve this problem by editing the file /etc/pam.d/lightdm and uncommenting the line:

#session required pam_loginuid.so

After rebooting I was able to use the Horizon client 8.5 (2203-8.5.0-19586897) without problems.

May 17, 2021

Priority tagging of vSAN traffic


According to Cisco COS is defined as "Class of Service (CoS) or Quality of Service (QoS) is a way to manage multiple traffic profiles over a network by giving certain types of traffic priority over others. "

Note that there's also a similar technology called DSCP that can used in more or less the same way.

When using a vSphere Distributed Switch it's possible to configure this and create fairly granular rules per Port Group. It's not at all limited to vSAN traffic even though that was our use case.


I was asked by the networking guys if we could enable this functionality for vSAN traffic by setting COS=3.


Identify the port group associated with the vmkernel adapter used by vSAN and choose  Edit Settings. / Advanced and enable Traffic filtering and marking. 

At configure level for the port group you will need to create the rule as outlined in the following steps:

Now that it was turned on it was instantly visible to the networking guys as they started seeing traffic within UC3 (Priority Group 3).

April 19, 2021

Autoinstall physical NSX Edge with custom passwords


Setting up NSX Edge in an automatic way with a custom password is a good idea because by default you get a default password that needs to be changed at first login. If you're planning on using an extra strong password, setting it through iDRAC (or similar) can be a bit awkward. If you're using a non-english keyboard layout (like me) it can be even more non-trivial to hit the correct special characters.


1. We had a problem getting the physical Dell R640 server with Mellanox 25GbE nics to boot from PXE. It would say "Booting from PXE Device 1: Integrated NIC 1 Port 1 Partition 1 Downloading NBP file... NBP File downloaded successfully. Boot: Failed PXE Device 1: Integrated NIC 1 Port 1 Partition 1 No boot device available or Operating system detected. Please ensure a compatible bootable media is available."

2. VMware has provided us with a nice 19 step document that guides us through the needed steps for setting up everything we need. The optional step 16 of setting a non-default password is however a bit misleading (probably referring to an older version of NSX?) and doesn't quite work.


1. In order to get the physical server to PXE boot we had to change the boot mode from UEFI to BIOS.

2. I had a case open for months without a resolution. In the end I started studying the Debian manuals (that the NSX Edge installer is based upon). I eventually found a working solution. It turned out that adding the following commands to preseed.cfg right after the "di passwd/root..." line gave a working config:

d-i preseed/late_command       string \
        in-target usermod --password 'insert non escaped password hash here' root;\
        in-target usermod --password 'non escaped password hash' admin
You will need to create the password hash using mkpasswd -m sha-512 as described in the original 19 step document.