ESX | Ray Heffer

How to pass the VMware VCAP-DCD exam (it’s tough!)

Posted on 28.Oct 2011 by Ray Heffer in ESX, ESXi, VCAP-DCD, Virtualisation, VMware

VMware Certified Advanced Professional - Datacenter Design (VCAP-DCD) Since the days when exams were written with chalk and slates and blog posts were cave paintings, it is obligatory to share the experience of taking exams within the community. I hope the title didn’t get you too excited as I signed an NDA and really can’t tell you how to pass this exam. But, what I can do is give you advice and help you focus your study where it really matters. For starters, if you are reading this then you are probably wondering about the VCP5 and the VCAP5 exams. I wouldn’t blame you if you are opting to hold on for the release of the VCAP5 exams, but as it stands whilst I write this post we have no idea when they will be released. It’s likely to be next year sometime, but that is a pure guess. Gregg over at TheSaffaGeek has already started compiling some material to help you with studying for the VCAP 5 exams. However, if you have decided to jump straight in and sit the VCAP-DCD4 (VDCD410) exam then here are my thoughts.

This exam is HARD-ass. There are a few peeps that say it’s easy, but I personally found this harder than the VCAP-DCA due to the shear number of questions (113 in total as stated in the blueprint). If you are a native English speaker then you get 3 hours 45 minutes (4 hours for non-native), and the key to passing this exam is primarily being able to skim-read a case study or scenario and understand design requirements, constraints, risks, assumptions and translate these into one or more of the possible answers. If you spend time reading each question in detail then you are likely to run out of time. It’s also a hard exam to study for because it tests your general experience with vSphere and design knowledge, so you are not just remembering where something is configured.

2.1 VCAP-DCA Study Guide – Implement and Manage Complex Virtual Networks

Posted on 20.Sep 2011 by Ray Heffer in ESX, ESXi, VCAP-DCA, Virtualisation, VMware

Networking is a critical component of any virtual infrastructure, and often it’s the management networks that are overlooked. Back in the day before virtualisation, management networks were considered less important than production, and it wasn’t too much of a big deal as it only provided console access (E.g. iLO, DRAC), SNMP monitoring, web interfaces, and so on – it just didn’t impact production. I have noticed that this mindset has crept into some vSphere designs where management interfaces lack any form of redundancy. Why is this so important? Well for starters ESXi uses the Management network for vMotion, Fault Tolerance (FT) and HA. In fact if your management interface has no redundancy you’ll get a warning as described in VMware KB 1004700. Without redundancy on your management networks, these features will not work. In addition, you may be faced with mixed ESX and ESXi environments where the management networks are different between ESX/ESXi. Management on ESX uses the Service Console network, but ESXi uses a vmKernel network called Management Network. Duncan Epping of Yellow Bricks has an excellent article on VMware HA here, also check out Frank Denneman and Duncan Epping’s HA and DRS Technical Deepdive book is an excellent read and I recommend this especially if you’re studying for the VCAP-DCA.

1.3 VCAP-DCA Study Guide – Configure and Manage Complex Multipathing & PSA Plug-ins

Posted on 16.Aug 2011 by Ray Heffer in ESX, ESXi, VCAP-DCA, Virtualisation, VMware

This section on storage continues on from section 1.2 in the blueprint (Manage Storage Capacity in a vSphere Environment) which at the time of writing these study notes, I haven’t completed yet. I felt that managing multipathing and PSA plugins deserves more attention, at least for me anyway. This is very command line heavy but remembering that during the VCAP-DCA exam documentation is provided (see key materials below), and the fact you can use command line help makes this a little less scary. Just try and remember what you need to achieve and have a good idea of which commands are used!

Knowledge Required

Explain the Pluggable Storage Architecture (PSA) layout

Key Focus Areas

Install and Configure PSA plug-ins
Understand different multipathing policy functionalities
Perform command line configuration of multipathing options
Change a multipath policy
Configure Software iSCSI port binding

Key Materials (VMware PDF’s & KB articles)

4.3 VCAP-DCA Study Guide – Configure a vSphere Environment to support MSCS Clustering

Posted on 12.Aug 2011 by Ray Heffer in ESX, ESXi, VCAP-DCA, Virtualisation, VMware

I remember when I first started using Microsoft Cluster Servers with SQL 2000 and Exchange 2003, and I had plenty of experiences (good and bad) especially once when I lost the quorum disk and I was due to go on holiday the next day! When I saw this topic on the VCAP-DCA blueprint I thought ‘oh’. Funnily enough, whilst I have had plenty of experience with physical clusters, I’ve never had to implement clustering in a vSphere environment. Due to certain complexities of MSCS you can achieve unwanted downtime (such as when I lost the quorum disk, or through mis-configuration) and can be a headache in itself. I’m not sure to what level the VCAP-DCA exam will require us to configure MSCS, but I am confident that it’s just configure the vSphere environment and not the other things you would normally have to do (SAN zoning, shared quorum disk, etc).

The first and only document I will use for this section on MSCS is Setup for Failover Clustering and Microsoft Cluster Service, and it’s only 36 pages so don’t worry you won’t be spending the next three weeks on MSCS alone! In fact, the VCAP-DCA blueprint lists each section in order on this document so it’s a safe bet!

1.1 VCAP-DCA Study Guide – Implement and Manage Storage, part 2

Posted on 26.Jul 2011 by Ray Heffer in ESX, ESXi, VCAP-DCA, Virtualisation, VMware

This is the second part to my VCAP-DCA study guide on storage (section 1.1 of the blueprint). As mentioned in part 1, I intend to focus these study notes on what you need to know with essential learning points. There is a big section on LUN masking using PSA related commands in this part of my study guide, and also an introduction to analysing performance stats with esxtop. Whilst esxtop is covered in many of the VCAP-DCA blueprint sections, 1.1 is the first section it is mentioned in regards to assessing storage performance, so at the very end of this post I have included the topic ‘Using ESXTOP for Storage Performance Analysis’.

1.1 VCAP-DCA Study Guide – Implement and Manage Storage, part 1

Posted on 04.Jul 2011 by Ray Heffer in ESX, ESXi, VCAP-DCA, Virtualisation, VMware

This is the very first subject on the VCAP-DCA blueprint, and I intend to focus these study notes on what you need to know with essential learning points. Throughout my study notes I have made a few assumptions about the reader. You will:

Already have a good grasp of vSphere and are comfortable using the vSphere client.
Have a good understanding of storage types, RAID levels, iSCSI, fiber channel, NFS.
Have some basic Linux knowledge, such as using Vi or Nano, and navigating around the file system.
Not be very familiar with using the vMA, PowerCLI, Service Console, or DCUI (at least not for anything advanced).
Need further guidance on using ESXTOP / RESXTOP and other performance and troubleshooting methods.

With that in mind I recommend that rather that following the exam blueprint in order, you try and focus on the topics you find the hardest. If I’ve not included notes on some topics (RAID for example) it is because there is already a wealth of information available. This way, your VCAP-DCA study can be focused on key learning points that target gaps in your knowledge or areas of weakness. Also bear in mind that at the time of writing this I haven’t taken the VCAP-DCA yet, but as a former virtual infrastructure team lead and admin, in addition to recent knowledge in the field I hope my notes help not only myself, but others to pass the certification too.

VMware ESXi 4.1 Kickstart Scripted Deployment with UDA (PXE BOOT)

Posted on 18.Mar 2011 by Ray Heffer in ESX, ESXi, Linux, Scripts & Commands, Tech Tips, Virtualisation, VMware

If you are looking to deploy multiple ESX/ESXi servers then there are plenty of methods and tools out there, some more complex than others. There are vendor specific deployment products available such as HP Rapid Depuployment Pack (RDP) which uses Altiris, or alternatively there are free deployment tools such as ESX Deployment Appliance (EsleeDA) and Ultimate Deployment Appliance (UDA). UDA is my favorite tool for the job as it offers great flexibility such as the use of subtemplates (discussed later), and therefore this will be the basis of this article. It was created by Carl Thijssen and thanks to Mike Laverick of RTFM, it also supports ESX/ESXi deployments, and the latest build supports ESX/ESXi 4.1.

Changing text typing repeat delay on a VMware virtual machine

Posted on 17.Mar 2011 by Ray Heffer in ESX, ESXi, Tech Tips, Virtualisation, VMware

If you find that when typing text using the VMware virtual machine console on a low bandwidth connection, it repeats characters (no matter how careful you are). Try setting the following configuration parameter:

keyboard.typematicMinDelay = 2000000

You’ll need to power off your VM first, then add this to the end of your configuration (.vmx) file. If you are using VMware ESX/ESXi then edit the settings of the virtual machine and go to Options then Advanced, General > Configuration Parameters.

VMware KB 196: http://kb.vmware.com/kb/196

8.3 VCAP-DCA Study Guide – Configuring vMA for Logging

Posted on 07.Mar 2011 by Ray Heffer in ESX, ESXi, Linux, Scripts & Commands, VCAP-DCA, Virtualisation, VMware

In this article I detail the steps required to configure your vMA as a Syslog server, and configure your ESX/ESXi hosts to send logging information to the vMA. Logging is often overlooked, but when managing multiple hosts it is far easier to send your logs to a Syslog server. I’m studying for the VCAP-DCA exam, and using vicfg-syslog is a requirement of the exam (Section 6.1) and the vMA is also essential to understand (Section 8.1). I hope my notes help you as they have helped me.

8.3 VCAP-DCA Study Guide – Introduction to vMA (vSphere Management Assistant)

Posted on 24.Feb 2011 by Ray Heffer in ESX, ESXi, Tech Tips, VCAP-DCA, VMware

VMware vMA (vSphere Management Assistant) The vSphere Management Assistant (vMA) runs a 64 bit operating system (RedHat Enterprise Linux) and features the VMware vCLI in addition to vSphere SDK for Perl, Java JRE, CIM vSphere profiles, VMware tools and an SNMP agent. The vMA virtual machine requires a single vCPU with 512MB memory and a 5GB virtual disk. If you are studying for the VCAP-DCA exam then you will need to know how to install and use the vMA to manage a vSphere environment. The best way to learn how to use the vMA is to setup your own home lab. I’ve already posted an article on building a whitebox VMware vSphere server for your home lab (click here), otherwise you can always use VMware Workstation on your PC or laptop.

VMware vSphere 4.1 Update 1 released today

Posted on 10.Feb 2011 by Ray Heffer in Business & IT, ESX, ESXi, Virtualisation, VMware

VMware vSphere VMware have released vSphere 4.1 Update 1 which adds support for additional operating systems (RHEL 6, RHEL 5.6, SLES 11 SP1 for VMware, Ubuntu 10.10, and Solaris 10 Update 9). ESX/ESXi 4.1 Update 1 now supports 160 logical processors. Looking at the number of patches for ESX and ESXi below, it makes me wonder whether this will be the last release of ESX, in favour of ESXi?