Troubleshooting

Visual Studio Code Error "No match was found for the specified search criteria and module name PackageManagement"

by Florian Grehl
July 7, 2020

Visual Studio Code asks to perform an update when launching the PowerShell Integrated Console. The Update fails with the following error message:

PS> powershell.exe -NoLogo -NoProfile -Command 'Install-Module -Name PackageManagement -Force -MinimumVersion 1.4.6 -Scope CurrentUser -AllowClobber'

PackageManagement\Find-Package : No match was found for the specified search criteria and module name 'PackageManagement'. Try Get-PSRepository to see all available registered module repositories.

Get-PSRepository returns the following error:Read More »Visual Studio Code Error "No match was found for the specified search criteria and module name PackageManagement"

Solution: ESXi Installation with USB NIC only fails at 81%

by Florian Grehl
July 6, 2020
13 Comments

When you try to install ESXi 7.0 with a USB NIC only, the installation fails at 81% with the following error message:

Exception: No vmknic tagged for management was found.

Some homelab systems like the Intel 10th Gen NUC are not equipped with a compatible network adapter. As a workaround, you can use a USB NIC and create a customized image to install ESXi. The installation fails as the ESXi installer can't assign the USB NIC as a management adapter because it specifically searches for a "vmnic#", not "vusb#" adapter.

This article explains how to proceed with the 81% installation error and get the system to work.

ESXi Update Error "[Errno 28] No space left on device"

by Florian Grehl
June 29, 2020
7 Comments

When you try to install a VMware ESXi Update using esxcli, the upgrade fails with the following error message:

"[Errno 28] No space left on device"

The problem is caused by ESXi not having enough free space available to extract the installation packages. This article explains how to solve the issue by enabling swapping to a Datastore.

Retrieve VMware Virtual Machine Password from OVF properties

by Florian Grehl
June 14, 2020

When you deploy a Virtual Machine from OVF/OVA you can sometimes preconfigure passwords using OVF properties. All configuration parameters set during the deployment can be viewed later in the Web Client within VM > Configure > Settings > vApp Options but when you want to retrieve the password, the actual value is hidden:
You can't access the password from the Client, MOB, or using the API. This article explains how you can retrieve vApp option passwords from the vCenter Database.

Manage vCSA Embedded vPostgres Database with pgAdmin

by Florian Grehl
May 14, 2020May 15, 2020
2 Comments

This article explains how to prepare the vCenter Server Appliance to connect with external Postgres Management Tools like pgAdmin. This method works with vCenter Server Appliance version 6.5, 6.7, and 7.0.

SCSI Sense Code Decoder OP Code Update

by Florian Grehl
September 2, 2017
3 Comments

I've added a new feature to my online SCSI Sense Code Decoder. It is now possible to enter the Command that has been reported to… Read More »SCSI Sense Code Decoder OP Code Update

Ping from specific VMkernel adapter in vSphere 6

by Florian Grehl
May 1, 2016May 1, 2016
5 Comments

When troubleshooting network problems on ESXi hosts you want to specify the outgoing VMkernel adapter. As explained here you can ping from a specific VMkernel adapter with the -I parameter. In vSphere 6.0, or with VXLAN activated, this might not work as expected and displays the following error.

[root@esx:~] ping -I vmk1 10.1.1.1
Unknown interface 'vmk1': Invalid argument

The problem is related to the multiple TCP/IP Stack features introduced in vSphere 6.0. To ping from specific VMkernel adapters that are not in the default Stack (defaultTcpipStack) you have to manually specify the NetStack with the -S parameter.

How long are Virtual Machines stunned for Snapshots and vMotion?

by Florian Grehl
October 28, 2015August 25, 2020
3 Comments

I've read this excellent article by Cormac Hogan explaining why and when a Virtual Machine receives a "stun". This post is a follow-up explaining how you can determine the duration of a Virtual Machine stun on the most common vSphere functions:

Create a Snapshot
Delete a Snapshot
vMotion

What's Inside an ESXi vm-support Bundle?

by Florian Grehl
October 20, 2015October 20, 2015
3 Comments

When you open a Support Request (SR) at VMware, the Global Support Services usually requests you to collect diagnostic information. You can create this log bundle with a special command line tool (vm-support), with the vSphere (Web-)Client or with the API. No matter how you create the bundle the result is always the same: a .tgz file containing your ESXi Host name and the creation date with a size of about 30 - 300MB.

This post explains what's inside this log bundle, but instead of simply extracting the file and looking at the result, I am going to take a look on how the file is created and what's part of the process.

Why is it important to know? Because it does not only contain data that allows VMware GSS to identify your issue, but also to help yourself to enhance your troubleshooting skills. The script gathers the output of many useful commands and there is nearly no black magic involved. You do not need special tools or internal VMware knowledge to make use of this log bundle.

ESXi Network Troubleshooting with tcpdump-uw and pktcap-uw

by Florian Grehl
October 14, 2015October 14, 2015
7 Comments

This post explains how you can troubleshoot network problems by capturing network traces of ESXi host by using the tcpdump-uw and pktcap-uw utility. The pktcap-uw tool is an enhanced packet capture and analysis tool that can be used in place of the legacy tcpdump-uw tool. The pktcap-uw tool is included by default in ESXi 5.5 and later. This post explains the main differences of both tools and how to use them.

tcpdump-uw vs. pktcap-uw - It's not the same!

The tcpdump-uw utility captures traffic from VMkernel adapters. The pktcap-uw utility, introduced in ESXi 5.5 can capture traffic that flows through physical network adapters, VMkernel adapters, and virtual machines adapters.

But it's more complex...