For my first post of 2013, I have decided to dive straight into sizing for VMware View 5.1. If you are planning a VMware View implementation then at some stage you will need to look at sizing, and calculating factors like how many desktops per View desktop pool, in addition to network configuration and storage considerations. The purpose of this article is to discuss sizing and configuration maximums for VMware View 5.1. Since VMware ESX 3.x, a configuration maximums document has been published by VMware for each version of vSphere that details the supported maximums for networking, compute, storage, vCenter, host, and even vCloud Director. Because there is no single ‘configuration maximums’ document for VMware View 5.1, I have included reference documents and material at the bottom of this article.
This week I passed the VCAP-DCD5 exam, but having already passed the VCAP-DCD4 exam I actually found it a little harder than I expected. I can’t tell you any specifics of the exam itself (other than what is on the blueprint) but I would like to share my own study method with you. You will need to be VCP5 before you can take this exam (the limited time period that excludes this pre-requisite is almost up), but even if you have done the VCAP4-DCA/DCD before, you should take a fresh approach to the DCD5. Something that helped me a lot was my ITIL experience, as I’ve previously had key involvement with Capacity and Availability management, in addition to being ITIL v3 Foundation certified . I’ll touch on this in a moment, but bear in mind that this is a Design exam and not a technical exam. Sure there are many technical areas, such as system requirements that you need to be aware of, but you need to have experience at either producing designs for your own organisation, or consultancy at delivering designs for customers. Without this knowledge, you may struggle with some of the questions around best practice, or picking the ‘best’ answer from multiple possible correct answers.
It was announced this morning that the VDCD511 (VCAP5-DCD beta exam) is available to take from 13th February to 2nd March 2012. You can take it at VMware Partner Exchange 2012 in Las Vegas. When the final exam is released, for a limited time you won’t need to have a VCP5 certification as a pre-requisite. Even if you are not planning on taking this exam during the beta invitations, it’s a great opportunity to get studying. The blueprint does subtly differ from the VCAP4-DCD, and as with the previous exam you’ll be expected to understand the VMware design methodology.
Whilst working on a Vblock 300 implementation a few weeks ago I had an interesting conversation with one of the network architects at VCE and we discussed the subject of best practices surrounding 10Gb and 1Gb networking. Traditionally with 1Gb networking it is best practice to separate traffic on your ESX/ESXi hosts with vSwitches (or dvPortGroups) dedicated to each type of traffic (vMotion, Management, Storage, production networking) and typically designs will contain 6 to 8 NIC’s per host. With the introduction of 10Gb networking, I’ve noticed that some implementations have neglected to include some important design considerations regarding the use of 10Gb networking. Lets say for that we present 4 x 10Gb NIC’s to each host (these are vNIC’s in the Cisco UCS world) or we can present 6 x 1Gb NIC’s using traditional methods of separating the traffic into various dvportGroups. Which is best? Can we get away with just 2 x 10Gb NIC’s or do we need more? The key consideration here isn’t how many NIC’s (or vNIC’s) are presented to each host, but rather how much network bandwidth is available to each traffic type (i.e. vMotion, FT Logging, VM traffic) and critically how we control it.
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.
Today I took the VCP510 exam and passed, so I thought I would share my thoughts on this latest certification by VMware. Firstly, I’m in the middle of the VCAP exams, having just completed the VCAP-DCA4 and will soon start studying for the VCAP-DCD4. Why take the VCP exam based on a new version now? Well, mainly because I’ve already been on the VMware vSphere: What’s New [V5.0] course and most of the contents are still fresh in memory. Secondly having passed the VCAP-DCA4 exam, with the next one being design focused I can pretty much focus on design best practices regardless of the version (although there are obvious differences).
After spending a week working down-under in Perth, I managed to get some time off this week to recover from the jet lag, so what better way than spending a few days refreshing my memory and doing LOTS of lab work with vSphere 5!
Much of my focus was around the vSphere Storage Appliance (vSA), vCenter Server Appliance and Auto Deploy and I must admit after reading some other comments I didn’t focus too much on configuration maximums (still glanced over them).
I’m actually really looking forward to the winter this year, and it seems that 5 is the lucky number. The new iPhone 5 will be released, rumours suggest this will be on or around 15th October, and then there is the iPad 3 (ok, it’s not 5 but worth mentioning!) which should have a far superior retina display which will be great for reading PDF’s and studying with! I’m still using the iPhone 3GS and iPad 1 so my Xmas list is easy this year, whether I get what I want depends on how good I am!
In the virtual world, at least inside the cloud, VMware have released vSphere 5 and View 5, in addition to many other new products. With the up and coming release of Microsoft Windows 8 with it’s incredible boot time thanks to the way it shuts down in a hybrid shutdown / sleep state, I can only imagine the benefits this will bring to desktop virtualisation and end-user computing as a whole.
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.
Update: VCAP-DCA4 no. 386 (cool!)
Juggling work, travel, kids, and personal time, whilst trying to study for any exam is no easy feat especially when you have a family that demands your undivided attention. I’m sure many of you are all in the same boat. Despite that I managed to squeeze in a lot of time into my home lab and study for the VCAP-DCA exam, so it is possible (just damn difficult!). So to set the scene, I woke up early in a hotel in Ireland yesterday following an intense but enjoyable week working on Vblock, and I noticed an email from VMware certification on my phone… Opening that email and the attachment with the results seemed to take forever, but what a relief to see that I passed.
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!
- 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)
- iSCSI SAN Configuration Guide
- Fibre Channel SAN Configuration Guide
- vSphere vSphere Command-Line Interface Installation and Scripting Guide
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!