How to properly decommission a VMware ESXi Host

 ESXi, vCenter vCSA, VMware  No Responses »
Jan 112024
 
ESXi-Host-Decommission

While most of us frequently deploy new ESXi hosts, a question and task not oftenly discussed is how to properly decommission a VMware ESXi host.

Some might be surprised to learn that you cannot simply just power down and remove the host from the vCenter server, as there are a number of steps that must be taken beforehand to ensure a proper successful decommission. Properly decommissioning the ESXi host avoids orphaned objects in the vCenter database, which can sometimes cause problems in the future.

Today we’ll go over how to properly decommission a VMware ESXi host in an environment with VMware vCenter Server.

The Process – How to decommission ESXi

We will detail the process and considerations to decommission an ESXi host. We will assume that you have since migrated all your VMs, templates, and files from the host, and it contains no data that requires backup or migration.

VMware ESXi Host Decommission Procedures
VMware ESXi Host Decommission Procedures

Process in Short:

  1. Enter Maintenance Mode
  2. Remove Host from vDS Switches
  3. Unmount and Detach iSCSI LUNs
  4. Move host from cluster to datacenter as standalone host
  5. Remove Host from Inventory

Please read further for extended procedures and more information.

Enter Maintenance Mode

We enter maintenance mode to confirm that no VMs are running on the host. You can simply right click the host, and enter maintenance mode.

Remove Host from vDS Switches

You must gracefully remove the host from any vDS switches (VMware Distributed Switches) before removing the host from vCenter Server.

You can create a standard vSwitch and migrate vmk (VMware Kernel) adapters from the vDS switch to standard vSwitch, to maintain communication with the vCenter server and other networks.

Please Note: If you are using vDS switches for iSCSI connectivity, you must gracefully develop a plan to deal with this beforehand, either by unmounting/detaching the iSCSI LUNs on the vDS before removing the switch, or gracefully migrating the vmk adapters to a standard vSwitch, using MPIO to avoid losing connectivity during the process.

Unmount and Detach iSCSI LUNs

You can now proceed to unmount and detach iSCSI LUNs from the selected system:

  1. Unmount the iSCSI LUN(s) from the host
  2. Detach the iSCSI LUN(s) from the host

You will unmount only on the selected host to be decommissioned, and then detach the LUNs (again only on the host you are decommissioning).

Move Host from Cluster to Datacenter as standalone host

While this may not be required, I usually do this to let vSphere Cluster Services (HA/DRS) adjust for the host removal, and also deal with reconfiguration of the HA agent on the ESXi Host. You can simply move the host from the cluster to the parent datacenter level.

Remove Host from Inventory

Once the host has been moved and a moment or two have elapsed, you can now proceed to remove the host from inventory.

While the host is powered on and still connected to vCenter, right click on the host and choose “Remove from Inventory”. This will gracefully remove objects from vCenter, and also uninstall the HA agent from the ESXi host.

Host Repurposing

At this point, you can now log directly on to the ESXi host using the local root password, and shutdown the host.

How to Install the vSphere vCenter Root Certificate

 Certificates, ESXi, vCenter vCSA, VMware  1 Response »
Dec 082023
 
vCenter-Root-CA-Missing

Today we’ll go over how to install the vSphere vCenter Root Certificate on your client system.

Certificates are designed to verify the identity of the systems, software, and/or resources we are accessing. If we aren’t able to verify and authenticate what we are accessing, how do we know that the resource we are sending information to, is really who they are?

Installing the vSphere vCenter Root Certificate on your client system, allows you to verify the identity of your VMware vCenter server, VMware ESXi hosts, and other resources, all while getting rid of those pesky certificate errors.

Certificate warning when connecting to vCenter vCSA
Certificate warning when connecting to vCenter vCSA

I see too many VMware vSphere administrators simply dismiss the certificate warnings, when instead they (and you) should be installing the Root CA on your system.

Why install the vCenter Server Root CA

Installing the vCenter Server’s Root CA, allows your computer to trust, verify, and validate any certificates issued by the vSphere Root Certification authority running on your vCenter appliance (vCSA). Essentially this translates to the following:

  • Your system will trust the Root CA and all certificates issued by the Root CA
    • This includes: VMware vCenter, vCSA VAMI, and ESXi hosts
  • When connecting to your vCenter server or ESXi hosts, you will not be presented with certificate issues
  • You will no longer have vCenter OVF Import and Datastore File Access Issues
    • This includes errors when deploying OVF templates
    • This includes errors when uploading files directly to a datastore
File Upload in vCenter to ESXi host operation failed

In addition to all of the above, you will start to take advantage of certificate based validation. Your system will verify and validate that when you connect to your vCenter or ESXi hosts, that you are indeed actually connecting to the intended system. When things are working, you won’t be prompted with a notification of certificate errors, whereas if something is wrong, you will be notifying of a possible security event.

How to install the vCenter Root CA

To install the vCenter Root CA on your system, perform the following:

  1. Navigate to your VMware vCenter “Getting Started” page.
    • This is the IP or FQDN of your vCenter server without the “ui” after the address. We only want to access the base domain.
    • Do not click on “Launch vSphere Client”.
  2. Right click on “Download trusted root CA certificates”, and click on save link as.
    Link to download vCenter trusted root CA Certificates
  3. Save this ZIP file to your computer, and extract the archive file
    • You must extract the ZIP file, do not open it by double-clicking on the ZIP file.
  4. Open and navigate through the extracted folders (certs/win in my case) and locate the certificates.
    VMware vCenter Root Certificates
  5. For each file that has the type of “Security Certificate”, right click on it and choose “Install Certificate”.
  6. Change “Store Location” to “Local Machine”
    • This makes your system trust the certificate, not just your user profile
  7. Choose “Place all certificates in the following store”, click Browse, and select “Trusted Root Certification Authorities”.
    Screenshot to Place in Trusted Root Certification Authorities
  8. Complete the wizard. If successful, you’ll see: “The import was successful.”.
  9. Repeat this for each file in that folder with the type of “Security Certificate”.

Alternatively, you can use a GPO with Active Directory or other workstation management techniques to deploy the Root CAs to multiple systems or all the systems in your domain.

Procedure for Updating Enhanced Linked Mode vCenter Server Instances

 ESXi, vCenter vCSA, VMware, vSphere  6 Responses »
Mar 062023
 
VMware vSphere 7 Logo

You might ask if/what the procedure is for updating Enhanced Linked Mode vCenter Server Instances, or is there even any considerations that apply?

vCenter Enhanced Link Mode is a feature that allows you to link a total of 15 vCenter Instances in to a single, Single Sign On (SSO) vSphere domain. This allows you to have a single set of credentials to manage all 15 instances, as well as the ability to manage all of them from a single pane of glass.

When it comes to environments with multiple vCenter instance and/or vCSA appliances, this really helps manageability, and visibility.

Enhanced Linked Mode Upgrade Considerations

To answer the question above: Yes, when you’re running Enhanced Linked Mode (ELM) to link multiple vCenter Server, special considerations and requirements exist when it comes to updating or upgrading your vCenter Server instances and vCSA appliances.

Multiple VMware vCenter Server Instances (vCSA) Running in Enhanced Link Mode (ELM)
Multiple VMware vCenter Server Instances (vCSA) Running in Enhanced Link Mode (ELM)

Not only have these procedures been documented in older VMware documentation, but I recently reviewed and confirmed the best practices with VMware GSS while on a support case.

Procedure for updating vCenter with ELM

  1. Configure/Confirm that the vCenter File-Based Backup in VAMI is configured, functioning, and that you are creating valid file based backups.
  2. Create a manual file-based backup with VAMI
  3. Power down all vCenter Instances and vCSA Appliances in your environment
  4. Perform a cold snapshot of all vCenter Instances and vCSA appliances
    • *This is critical* – You need a valid offline snapshot taken of all appliances powered off at the same point in time
  5. Power on the vCenter/vCSA Virtual Machines (VMs)
  6. Perform the update or upgrade

Recovering from a failed Update

IMPORTANT: In the event that an update or upgrade fails, you must revert all vCenter Instances and/or vCSA appliances back to the previous snapshot!

You cannot selectively choose single or individual instances, as this may cause mismatches in data and configuration between the instances as they have databases that are not in sync, and are from different points in time.

Additionally, if you are in a situation where you’re considering or planning to restore previous snapshots to recover from a failed update, you should do so sooner than later. As time progresses, service accounts and identifiers update in the VMware vSphere infrastructure. Delaying the restore too long could cause this information to get out of sync with the ESXi hosts after performing a snapshot restore/revert.

vCenter OVF Import and Datastore File Access Issues

 ESXi, vCenter vCSA, VMware  1 Response »
Feb 252023
 
vCenter-Root-CA-Missing

When using VMware vSphere, you may notice vCenter OVF Import and Datastore File Access Issues, when performing various tasks with OVF Imports, as well as uploading and/or downloading files from datastores.

These issues can cause a number of symptoms including errors, unexpected status codes, and also just simply failing for an undetermined reason.

vCenter File Upload failed error "The Operation failed."
vCenter File Upload: The Operation failed.

The Problem

For this situation, the symptoms will occur when performing one of the following tasks:

  • Cannot Upload File to datastore
  • Cannot Download File from datastore
  • Cannot Import OVF Template
  • Cannot Export OVF Template

An example of errors that the user may see:

  • The operation failed for an undetermined reason.
  • The operation failed.
  • unexpectedStatusCode":0
  • unexpectedStatusCode (0)
  • HTTP 500 Error
  • NET::ERR_CERT_AUTHORITY_INVALID

See below for some example screenshots of errors you may see.

vCenter Error: "The operation failed for an undetermined reason."
The Operation failed: The Operation failed for an undetermined reason.
Chrome and vCenter report "NET::ERR_CERT_AUTHORITY_INVALID" error
“NET::ERR_CERT_AUTHORITY_INVALID”

Please note, that this condition can cause other issues and errors as well.

The Solution

When using VMware vSphere, the vCenter server acts as it’s own Root Certification Authority, and uses SSL certificates to facilitate communication and encryption between various services in the solution, as well as the communication between the vCenter Server, ESXi hosts, and any client computers accessing vCenter via the web HTML5 interface.

This Root Certification Authority running on the vCenter Server creates and issues certificates to these services and hosts, which are issues under the Root CA Certificate.

While vCenter automatically handles the certificate trusts between the services, as well as the communicate between the vCenter Server and ESXi hosts (this is automatically setup when adding hosts to vCenter), it cannot automatically make your (client) computer trust the entire certificate authority, as well as all the child certificates.

To resole this issue, you’ll need to follow my guide on How to Install the vSphere vCenter Root Certificate on your computer you are using to connect to the vCenter interface.

After installing the vCenter Root CA on your system, the issue will be resolved.

HPE Simplivity Upgrade Manager – Access Denied, Incorrect Credentials

 HPE, HPE Simplivity, vCenter vCSA, VMware  No Responses »
Jan 112023
 
HPE Simplivity Logo

When attempting to log in to your VMware vCenter using the HPE Simplivity Upgrade Manager to perform an upgrade on your Simplivity Infrastructure, the login may fail with Access Denied, Incorrect Credentials, or Incorrect Username and Password.

Despite confirming that the credentials are correct (logging in to the vCenter UI, as well as the vCSA console via SSH), the HPE Simplivity Upgrade Manager will continue to fail on connection.

The Problem

During the login process, the HPE Simplivity Upgrade Manager will not only check the credentials and attempt to logon to the vCenter server, but it will also attempt to pull and validate the SSL certificates (whether trusted or not) on the vCenter server.

During the typical login process, after entering the credentials and clicking “Connect”, the user will be prompted with the SSL certificate information asking to approve the connection. In this specific circumstance the SSL window is not presented.

HPE Simplivity Upgrade Manager Login Failed

Because of the SSL check not being presented, I thought there may have been a chance with trusting the connection, and possibly HPE Simplivity wasn’t able to show the error specific to the SSL check failing.

vCenter Download Trusted Root CA Certificates

When clicking on this, I was presented with an HTTP 404 error (File not found), meaning the certficiates weren’t present, which I felt may be contributing or causing this problem.

The Solution

After doing a quick search, I was able to find a VMware KB 89325 addressing the issue of being Unable to download Trusted Root Certificates for VCSA because it shows 0kb file.

Logging in to the vCSA appliance, I was able to determine that the appliance was missing the certificate symlink to allow the certificate download by running this command:

ls -ltra /etc/vmware-vpx/docRoot

Inside of the directory listing, there was no symlink for certs, which should point to “/var/lib/vmware-vpx/docRoot/certs”.

I went ahead and created the symlink using the following command:

ln -sfn /var/lib/vmware-vpx/docRoot/certs /etc/vmware-vpx/docRoot/certs

When using the “ls -ltra /etc/vmware-vpx/docRoot” command from above, I was now able to verify that the symlink existed:

vCenter DocRoot showing “certs” symbolic link

After creating the symlink, I was able to download the Trusted Root CA zip file (you don’t need to do anything with this file as the download was just a test).

I now went back to the Upgrade Manager to attempt to login, and it was successful.

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