powercli

This is a quick one. Sometimes you need to evacuate VMs from a host, do some maintenance, and redistribute the VMs to the originating host. This can be annoying, especially if you don’t have a vSphere Enterprise Plus license with DRS, DRS groups etc. These few PowerShell lines may help you. ,

TL;DR: There’s a script at the bottom of the page that fixes the issue. Some days ago, this HPE customer advisory caught my attention: Advisory: (Revision) VMware - HPE ProLiant Gen8 Servers running VMware ESXi 5.5 Patch 10, VMware ESXi 6.0 Patch 4, Or VMware ESXi 6.5 May Experience Purple Screen Of Death (PSOD): LINT1 Motherboard Interrupt And there is also a corrosponding VMware KB article: ESXi host fails with intermittent NMI PSOD on HP ProLiant Gen8 servers

Today, I had a very interesting discussion. As part of an ongoing troubleshooting process, console screenshots of virtual machines should be created. The colleagues, who were working on the problem, already found a PowerCLI script that was able to create screenshots using the Managed Object Reference (MoRef). But unfortunately all they got were black screens and/ or login prompts. Latter were the reason why they were unable to run the script unattended.

I’m not a developer. I deal mainly with infrastructe, things like virtualization, storage & backup, networking etc. Sometimes I had to write scripts, primarily PowerShell, batch or Bash. Many years back, I also wrote Csh and Ksh scripts. In the past years, automation was one of the rising trends in the infrastructure segment. And with automation, new challenges came up. Today I have to work with Windows PowerShell, in case of VMware with PowerCLI (which bases on Windows PowerShell), and sometimes I have use with REST APIs.

Careful preparation is a key element to success. If you restart a storage controller, or even the whole storage, you should be very sure that all ESXi hosts have enough paths to every datstore. Sure, you can use the VMware vSphere C# client or the Web Client to check every host and every datastore. But if you have a large cluster with a dozen datastores and some Raw Device Mappings (RDMs), this can take a looooong time.

DataCore describes in their Host Configuration Guide for VMware ESXi some settings that must be adjusted before storage from DataCore SANsymphony-V storage servers will be assigned to the ESXi hosts. Today, for ESXi 5.x and 6.0, you have to add a custom rule and adjust the advanced setting DiskMaxIOSize. For ESX(i) 4 more parameters had to be adjusted. But I will focus on ESXi 5.x and 6.0. You need to adjust these settings for each host that should get storage mapped from a DataCore storage server.

Disk space is rare. I only have about 1 TB of SSD storage in my lab and I don’t like to waste too much of it. My hosts use NFS to connect to my Synology NAS, and even if I use the VAAI-NAS plugin, I use thin-provisioned disks only. Thin-provisioned disks tend to grow over time. If you copy a 1 GB file into a VM and you delete this file immediately, you will find that the VMDK is increased by 1 GB.

While preparing for a VMware vSphere 5.5 update at a customer of mine, I stumbled over VMware KB2085618 (ESXi host cannot initiate vMotion or enable services and reports the error: Heap globalCartel-1 already at its maximum size.Cannot expand.). I checked the HP AMS version in the latest HP custom ESXi image and found out, that version hp-ams-esx-550.10.0.0-18.1198610 is included (source). Unfortunately the bug is not fixed in 10.0.0, but it’s fixed in 10.

Today I stumbled over a nice workaround. While installing a CentOS 6 VM, I needed to install the VMware Tools. I don’t know why, but I got an error message, regarding a non accessible VMware Tools ISO. Patrick Terlisten/ vcloudnine.de/ Creative Commons CC0 I remembered a blog post I read a few months ago, about a VMware online repository, from which VMware tools can be installed. You can download the repository information here.

Today I found this neat PowerCLI One-liner in my Twitter timeline: PowerCLI Einzeiler um den Adapter-Typ einer VM auf Vmxnet3 zu ändern: Get-VM YOUR-VM |Get-NetworkAdapter |Set-NetworkAdapter -Type "Vmxnet3" — T. Scheller (@bones44) February 28, 2014 A nice side effect of this one-liner is, that the mac-address doesn’t change, as you can see in the screenshots. Patrick Terlisten/ vcloudnine.de/ Creative Commons CC0 Patrick Terlisten/ vcloudnine.de/ Creative Commons CC0 If you have ever changed the adapter type of a vNIC you will know, that this leads to a changed mac-address and a new adapter in the OS.