Vsphere

I’m often asked about how to provision virtual machine disks. This almost always comes down to, “Should I use thick or thin disks?” and then “Should I do thin provisioning on the array or on the hypervisor?” So here we go: Thin vs Thick Thin provisioning: Thin provisioned disks don’t allocate all of the space during the provisioning of the storage. Instead, they allocate the space on demand. This is a great way to get more bang for you buck out of your storage. Let’s take a closer look with an example. ...

VMware slot sizes are an important topic if you’re concerned with how many ESXi hosts are required to run your environment. What is a Slot? To begin this post, we need to understand what a slot is. A slot is the minimum amount of CPU and memory resources required for a single VM in an ESXi cluster. Slot size is an important concept because it affects admission control. A VMware ESXi cluster needs a way to determine how many resources need to be available in the event of a host failure. This slot calculation gives the cluster a way to reserve the right amount of resources. ...

In my last post I explained a memory reclamation technique called Transparent Page Sharing. This post is dedicated to the Balloon driver method. The first thing to be clear about is that Memory Ballooning is a technique that is only engaged when the host is running low on physical memory. If you have a host with 60 GB of physical memory available and the virtual machines are only allocated a total of 30GB of memory, then you may never need to know what memory ballooning is all about. However if you are over committing your hosts then this is an important topic to review. ...

One of the companies I worked for got a Netapp filer and I loved the fact that it would dedupe the data that was sitting on disk. I got over 40% more storage just by having that sweet little feature on. I was thinking, “How awesome would it be to dedupe my memory?” Getting more memory out of my servers would be a nice thing. Well as it turns out, VMware does this already, but they call it “Transparent Page Sharing.” ...

When you team NICs together in ESXi 5 you can pick from a variety of load balancing techniques to determine how traffic should flow over the adapters. You might think that setting up software iSCSI initiators in ESXi would be done in a similar manner. Add a VMkernel to a vSwitch, add a couple of adapters and set a teamingfailover policy. It turns out that this is not the case. You could setup a software iSCSI initiator this way, but it won’t provide you the teaming or failover you’ve intended. ...

I just found out that I’ve passed the VMware Certified Advanced Professional 5 - Datacenter Administration exam and wanted to share my experience. When I first set out to take on this exam, I was apprehensive about it because of the number of possible questions that could be asked on it. The blueprint was quite large and covered basically everything related to vSphere. I got some helpful advice from a friend who told me that instead of worrying about if I could pass the exam, think about it like vSphere Olympics. It’s a chance to show off how much you know. It was a subtle change, but a different mindset really helped me. ...

Over the past few weeks, I’ve been hearing a lot of customers having issues logging into vCenter after upgrading to vSphere 5.1. I upgraded the lab and had some issues as well, but was able to fix the issues and wanted to share what I’ve learned. As you may know version 5.1 of vSphere requires the SSO service to be installed before vCenter can be upgraded. SSO is required for this version and cannot be skipped. ...

I recently tried out the HP Insight Control plugin for vCenter and was very pleased about the added functionality that was provided in my vSphere client. http://h18013.www1.hp.com/products/servers/management/integration.html This plugin gives you additional control of your HP servers and storage that are being used by your vSphere environment. Like other storage vendors, the install will configure your VASA plugin, and will also allow you to do things such as create datastores and snapshots on the storage array from the vSphere Client. ...

 I’ve written posts in the past regarding LUN masking on a storage array, but it is possible to mask a path directly from your vSphere environment. I feel that if at all possible the masking should be handled at array level because the array is closest to the disk. Let’s face it, if vSphere shouldn’t see a LUN for one reason or another, then why is the array presenting it in the first place? ...

vSphere AutoDeploy always seemed like a lot of work to setup just to deploy a few VMware hosts, but in my current job I don’t setup hosts very often. If you are constantly deploying new hosts to get out in front of performance issues, or are building a new datacenter and deploying many hosts at once, AutoDeploy can be a great way to get up and running quickly. Prerequisites In order to use AutoDeploy, you’ll first need vSphere5, the AutoDeploy Install (which is on the vCenter Media), the vSphere5 Offline Bundle, PowerCLI, a DHCP Server and a TFTP server for starters. ...