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).

The process of requesting certificates for vSphere 5.1 is a fairly grim, manual process. It’s repetitive and easy to make a mistake on any step of the way. Since I’ve got to do this for quite a few VirtualCenter Servers, I thought I’d script the certificate generation if nothing else. I am following the excellent documentation provided in Implementing CA signed SSL certificates with vSphere 5.1 and more specifically in Creating certificate requests and certificates for vCenter Server 5.

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:

I ran into this issue yesterday while reconnecting hosts in our vCenter Server following a complete reinstall - the reasons for which are a long story, but suffice to say that there were new certificates and the host passwords were encrypted with the old ones. The LUNs had been unpresented at the hardware level by the storage team, but had not been unmounted or removed from vCenter. This is not the way to remove storage - let me re-iterate: remove storage properly.

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.

Firewalls being used – Sonicwall 3500 & Cisco 506e Several months ago we relocated and it was then necessary to setup a Site to Site VPN tunnel with another network. (In this instance the other network was not directly managed by us) Upon the creation of the tunnel and after successful traffic tests all looked well. However after several hours or less in some cases traffic stopped flowing yet both firewalls reported the tunnel as “up”.

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.

Just a quick post regarding the vSphere Management Assistant 5 - when deploying the vMA with a static IP address, you might see the following error: Power On virtual machine Cannot initialize property ’ vami.DNS0.vSphere_Man- agement_Assistant_(vMA)’ , since network ‘’ has no associated IP pool configuration. Edit the vMA virtual machine’s properties and go to Options, vApp Options and select disable. Acknowledge the warning and click OK to close the VM properties.