vSphere

Had a strange one after deploying an XP VM from a template today - the VM would not power on and threw the following error: An error was received from the ESX host while powering on VM [VM name]. cpuid.coresPerSocket must be a number between 1 and 8 Digging around on google the error seemed to be related to over-allocating vCPUs (e.g. assigning 8 vCPUs on a VM with 4 physical CPU cores).

So VMware’s Support Assistant is pretty awesome and it’s free! I thought I’d do a quick run through of the installation and set up for anyone who was interested, it’s fairly straightforward and if you raise a lot of calls or have multiple calls on the go it’s a time saver! VMware’s official page for the Support Assistant is here - https://www.vmware.com/products/datacenter-virtualization/vcenter-support-assistant/overview.html The OVF deploy is so simple I’ve just taken screenshots:

I’m very pleased to say that as of 21st December, I passed my VCP510 exam and am now VCP5 qualified! It’s something that I’ve wanted to do for a long time (since VCP3) but have never been able to get funding for the required course. My current employer sent me on the vSphere 5 Fast Track course earlier this year, so I was all set to take the exam. My exam experience was somewhat marred by a very poor first attempt which I narrowly failed.

While adding an additional vCenter Server to our Multi-Site Single Sign On instance I encountered a problem as I entered the details of the existing SSO. The error thrown was: User credentials are incorrect or empty. Provide correct credentials. After a couple of hours online with VMware support I took a guess at the problem. On the existing Single Sign On Configuration I have added the Active Directory domain DefinIT and in order to enable integrated authentication from the vSphere Client I moved it to the top of the list - this meant that System-Domain is no longer the default authentication domain.

I’ve been learning my vSphere 5 config maximums before my upcoming VCP5 exam, so in a supreme effort of procrastination I thought I’d write a PowerShell quiz script: here it is! Save the QuizMe.ps1 file into a folder and then place one or more text file in the same folder containing a comma delimited set of questions and answers. Then run QuizMe.ps1! You can choose the quiz you take (which text file it will use).

VMware vSphere Single Sign On (SSO) can be installed in Multi-site mode to support local sign-on to vCenters that you want to be part of the same single sign on domain - for example, if you want to install Linked-Mode and have the advantage of a single pane of glass view, but can’t risk using a single SSO instance across the WAN. In other words, from VMware’s blog post:

So recently we upgraded our cluster monitoring suite to it’s latest iteration (Veeam ONE), it was not long before I began to receive emails from the monitor informing me of Host disk write latency “errors” (Datastore write latency had exceeded the defined threshold in the monitor) on several of the Datastores on our SAN. Naturally I began the process of cross referencing backup routines and any heavy I/O routines that may have been running at the time the warning messages were generated.

One thing we have been meaning to do for a while but haven’t got round to is getting our Virtual Center Servers into “Linked” mode - essentially to provide a single pane of glass view of our entire virtual estate. One vCenter resides on the other side of our DMZ and manages hosts isolated for security purposes. I’ve created an IPSec server-to-server connection and allowed that through the firewall to secure traffic between the DMZ VC and LAN VC.

In vSphere 5.1 “Tags” replace the old custom attributes to provide a way of adding metadata to vSphere objects. The “Tags” are organised into categories to “define how the tags can be applied to inventory objects”. The easiest way to think of the difference is that custom attributes are “free text” and the tags are statically defined properties. There is a wizard for converting custom attributes to tags, but it can get a bit confusing and is pretty poor - let me explain.

Here’s a lesson in checking the basics! I added new ESXi 5 host to a cluster today and spent a good couple of hours troubleshooting the error: vSphere HA agent for host [Host’s Name] has an error in [Cluster’s Name] in [Datacenter’s Name]: vSphere HA agent cannot be correctly installed or configured After a few basic checks, migrating the host in and out of the cluster and rebooting, I headed off to google and began troubleshooting.