VMware VCAP5-DCA Experience

This morning I received a much anticipated email from VMware Certification. It had been almost three weeks since re-sitting my DCA exam and I was extremely nervous about the result.

My first attempt at the exam was terrible and it really threw me. At the time the lab environment was very slow and I panicked, wasting valuable time just thinking about the time! After that I was totally put off the experience and put my study on hold. In fairness I had just had another baby so I cut myself a little slack 🙂

Anyway, three months went by and I geared up once more to attack the beast. I sat the exam at the same testing centre in sunny Tauranga, New Zealand (seems to be the ONLY place you can actually book the exam in NZ anyways). This time the lab environment seemed much faster at responding and I found myself getting through questions far quicker. To be fair I had also put more study into the areas that I had clearly lacked from the first attempt and this made a lot of difference.

The exam was still extremely tough and it was clearly a very different set of questions and lab setup from the first time. I managed to run out of time with about five questions left completely unanswered. I still felt very nervous about how I did but hoped that I had done enough to pass, in this case more than 300/500. My first attempt came in at about 250/500 but I had only answered about 60% of the questions, so I was hopeful that this time was much better.

So, this morning I was up at about 6am with my two boys, half asleep sitting on the couch. I’m on my phone using the web browser to view webmail (don’t ask!) and the attached pdf result wouldn’t download!!!! Then when I finally managed to get it to download it wouldn’t open the pdf, argh!!!!!! I finally got the thing open and scrolled down to the score…389/500, woohoo!

I was so stoked, I really didn’t want to have to sit it a third time! Now that I have both DCD and DCA I can now apply for VCDX. This will be my next major goal and realistically will take me some time. Between a busy job and family life there ain’t a lot of time left for preparing a design, but lets hope that through work I can prepare one suitable.

Finally, to give my two cents worth of advice to others out there considering taking the exam;

1. Work through the blueprint end to end, and I really do mean end to end. The exam covers stuff from all over the blueprint (go figure :-P)

2. Check out Jason Langer and Josh Coen’s study guides here: http://www.valcolabs.com/vcap5-dca/ and here: http://www.virtuallanger.com/vcap-dca-5/, both of these guys fricken rule! Many thanks to them for their massive efforts in creating such a great resource.

3. Use Autolab for creating your home lab environment, it will save you a heap of time: http://www.labguides.com/. A BIG thanks to Alastair Cooke for his work and others that have helped him. It is a fantastic tool for deploying vSphere at home.

4. Make sure that you don’t skip over areas that you think you already know. I did this both times and realised afterwards that I didn’t really know as much as I thought I did!

5. During the exam, manage your time very carefully. Don’t stall on any one particular question too long and if you get stuck, move on and come back later.

6. Oh, and lastly, if you do fail, don’t beat yourself up. It’s a real tough exam with a lot of content to work through in a short space of time. I was way too hard on myself the first time and this put me off getting back in the drivers seat for a long time. Sometimes it is good to fail and gives us perspective.

We’ll that’s about it from me, I’m over the moon about passing and I can sit back for a little while now…just not too long eh! VCDX…

Study hard and good luck!

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vSphere Home Lab: Part 3 – Procurves and static routing

So I’ve just spent the last three hours trying to work out why my Procurve switch wasn’t routing my various VLAN’s I have configured for my home lab.

I had to move my three hosts and switch into the garage because the heat in the office was becoming unbearable! Unfortunately because of this I broke my connection to my iSCSI VLAN I had configured for my labs ip storage. Because I’m running my SAN management software on my main pc I had a second nic directly plugged into that VLAN, nice and simple right?

However, when I moved the gear I no longer had two cables running to my main pc, I now only had one. I though to myself, “surely I can set up some static routing!?!?”.

Anyway, as it turns out my little Thomson ADSL router supports static routing, cool! I configured this like so:

:rtadd 192.168.3.0/24 192.168.2.50 (where 192.168.3.0/24 is my iSCSI subnet and 192.168.2.50 is the management ip of the Procurve). Step one done!

Next I jumped onto my Procurve 2910al and enabled ip routing, giving me this config:

hostname “SWITCH1”
module 1 type j9147a
no stack
ip default-gateway 192.168.2.1
ip route 0.0.0.0 0.0.0.0 192.168.2.1
ip routing
snmp-server community “public” unrestricted
spanning-tree legacy-path-cost
spanning-tree force-version stp-compatible
vlan 1
name “DEFAULT_VLAN”
no untagged 25-36
untagged 1-24,37-48
ip address 192.168.2.50 255.255.255.0
exit
vlan 10
name “vMotion”
tagged 13-18
no ip address
exit
vlan 20
name “FT”
tagged 13-18
no ip address
exit
vlan 30
name “iSCSI”
untagged 25-36
ip address 192.168.3.1 255.255.255.0
exit
management-vlan 1

Now, doing a tracert from my main pc on VLAN1 it would get as far as the Procurve, but the switch would respond with destination net unreachable.

I continued to try different commands and read several blog posts on configuring static routes and everything I had done looked fine!

I finally came across a comment someone had posted on a forum suggesting that when you specify a management VLAN on the switch it breaks routing! ARGHHHHHHH!

So, I ran “no management-vlan 1” and saved the config. Now the switch is properly routing all VLANs, yay!!!!!

Now I can fire up my HP P4000 CMC and connect to my VSA’s from my main pc on VLAN1, woohoo.

vSphere Home Lab: Part 2 – There’s some junk in my trunk…

Well, I finally received the last few bits I needed to finish building my new vSphere hosts, in particular my nice little two-bay 2.5″ to 3.5″ drive adapters. These babies cost me about five bucks a piece and means I can mount two SSD’s in a single 3.5″ slot, cool.

Anyway, I started configuring my network based on the fact that I wanted to “trunk” two ports per host so that I had the native VLAN1 untagged, as well as several other tagged VLANs for my vMotion, FT, etc. Please note that trunking VLAN1 to a production ESX host is not recommended, mostly due to the potential security risks around VLAN hopping. I’ve read several VMware documents referring to not trunking VLAN1 however some say “don’t do it” and others say “it won’t work”. I can tell you that it DOES work and could be used in a production environment where the business limitations demand it. One such area would be where there is a large amount of existing network infrastructure using VLAN1 and would be too costly to change (yes, we have some instances of this :-P).

Anyway, back to my lab. I have some pretty crap home networking gear that these HP switches are plugging into and as such don’t support VLAN’s, hence why I am using the native VLAN1. I spent hours the other night trying to work out how to “trunk” several ports and really struggled. To give you some background here, I am not a network engineer and do not administer/configure switches in my day job, however, I understand enough to know how some things work :-). Most of our environment at work involves Cisco switches and because of this I am used to Cisco terminology. This is where I came unstuck…

When we “trunk” ports in a Cisco to pass multiple VLAN’s we are aren’t actually creating an Etherchannel or LACP trunk, instead we are assigning tagged VLAN’s to a port or multiple ports. While trying to stumble my way through using these HP’s I had that same philosophy in mind and could not work out why my “trunks” weren’t working!

As it turns out Cisco do things completely the opposite to most other vendors, such as HP. In the HP switches, you create a VLAN, and assign ports to the VLAN, whether tagged or untagged. I found this blog post which completely explains it all: http://networkingnerd.net/2011/02/02/when-is-a-trunk-not-a-trunk/

So, to cut a long LONG story short, I now consider myself OWNED by these switches and now understand the differences between Cisco’ism and the rest of the world when it comes to trunking, access ports and trunk ports!

Whew…now back to the cool stuff (just kidding, I actually enjoyed it!), playing with vSphere!

Oh, by the way, I’ve given up on running two switches, it’s too noisy and hot, and to be honest, I wouldn’t gain much for the purposes of my VCAP-DCA study, so I’m keeping it simple with one switch…

Thanks for reading, stay tuned for future posts, my next one will probably talk about building up the VSA’s.

vSphere Home Lab: Part 1

After getting the VCAP5-DCD exam out of the way I started to work out what hardware I’d buy for creating a new home lab for my DCA study. Up till now I have used my main gaming rig as a home lab, running an 8-core AMD FX cpu and 32GB of RAM. While this has served me well it isn’t ideal and doesn’t have the flexibility I’d like.

I started trawling through numerous blogs about other home labs and liked the idea of using the Supermicro uATX motherboards that support the E3 Xeons and IPMI. However, after a lot of looking mostly on Amazon (here in NZ the only place I could find boards from was going to cost me almost $400 NZD per board…) I gave up. It was going to be too risky ordering pc gear from overseas and not have the confidence I’d get the right memory modules, etc. Don’t get me wrong, I’d love to have some, in particular the MBD-X9SCM-iiF as it has the two onboard 82574L LAN ports as well as the dedicated IPMI port. But for what I needed I could not justify almost doubling my budget, particularly as the E3 Xeons, such as the E3-1230 would set me back almost $400 NZD a piece too.
Instead I opted for more AMD based gear 🙂
Here is the spec I came up with:

3 x AMD FX 6100 Six-core CPU 3.3ghz – $180 NZD each

3 x Gigabyte GA-78LMTUSB3 – Nice uATX form factor, supports FX cpus, can take up to 32GB DDR3 with support for ECC un-buffered RAM – $115 NZD each

3 x Coolermaster 343 uATX cases (these are pretty cheap and are reasonably small) – $97 NZD each

6 x OCZ Vertex2 120GB SSDs – I got these because they were on special for $114 NZD each 🙂

6 x 8GB DDR3 1333mhz non-ECC – These were about $65 NZD each. Couldn’t afford to go with ECC and didn’t feel I really needed it…when money permits I’ll be upgrading each host to 32gb RAM

3 x HP NC364T 4 port GbE NIC’s – I’m using some spare ones from work

2 x HP ProCurve 2910al-48G switches – Another loaner from work 😛 We had these surplus and aren’t planning on deploying them anywhere

3 x HP P4000 VSA licenses – Yet another thing I was lucky to get from work, we had three licenses we purchased a while back and ended up putting physical P4300 SAN’s in so I figured these would be perfect in a home lab!

Here’s a few pics of the gear so far. Excuse the poor quality photos…my HTC Sensation’s camera is not working that well running a beta JB ROM 🙂

HP Procurve 2910al-48G

HP switches – sweet!!!!

My three vSphere hosts

Cool, VCAP-DCA here I come!

The guts

Cheap and cheerful, no frills at it’s best! Notice I haven’t installed the additional NIC card or the SSDs…where’s my adapters!!!!!

All up I’ve spent close to $2500 NZD which isn’t too bad, but certainly not a cheap exercise…oh well, it’s going to be a great tool for learning so it’s worth it for that!

Bear in mind that most of these parts won’t be on the VMware HCL but this isn’t a production environment, and as such they don’t need to be.

So, I’ve got all the gear mostly built other than waiting on some 2.5″ to 3.5″ SSD drive adapters (the cases don’t have 2.5″ bays 😦 ) and I screwed up with one of the cases. I accidentally purchased the wrong model (I initially purchased only one case as a test) and didn’t realise that the power supply included didn’t have a 4+4 12v molex plug for the cpu power…argh! I’ve got an adapter cable coming that will fix the problem though. I also have three 4gb USB sticks on order too for the hypervisor to boot from. This will mean I can allocate as much of the SSD storage as possible to the VSA’s.

At this stage I think I’ll configure the VSA cluster volumes using NRAID5 (for those of you who haven’t used the HP Lefthand gear it supports various network RAID levels when using multiple nodes) as this will give me close to 400GB of SSD storage. I’ll enable thin provisioning on both the datastores and in the VSAs so I should get a reasonable number of VM’s on it.

If you are wondering “but what about TRIM support?” I have thought about this. It seems that vSphere does not support the TRIM command but to be honest I don’t really care. I figure it will probably take me a while to kill them and they do have a three year warranty :-). At one stage I was going to build a FreeNAS server or similar with all the SSDs (which does support TRIM) but I thought I’d get more out of running the VSAs. Since I use P4300 SANs at work this would give me more opportunity to play around with the software and different configurations.

As for the network configuration, I haven’t quite decided my layout yet. I am probably going to trunk two nics for Management, vMotion, FT and VM traffic, possibly leaving two nics for iSCSI. I probably won’t get the same benefit out of using two nics per host for iSCSI as I would with a physical SAN as the VSA only supports one virtual network adapter (i think…it’s been a long time since I looked at it) but I will still be able to simulate uplink failure, etc.

Anyway, I better get back to trying to configure these switches…went to plug my rollover cable into them and realised my pc doesn’t have a serial port…doh!
Stay tuned for part 2, building the hosts and setting up the VSA 😉

VCAP-DCD/DCA Home Lab – What should it look like?

I thought I’d create some discussion around what others thought a VMware home lab should consist of. When I studied for my VCP5 exam I had the following:

– Main desktop pc with Workstation 8, 8-core CPU with 16GB RAM, 1TB disk drive

– Domain controller VM running 2k8R2, with DNS and DHCP roles. Also had the Solarwinds free FTP server for Autodeploy. This VM had 1 vCPU, 2GB vRAM and 20GB disk. With this it ran ok, didn’t need to be any bigger.

– vCenter Server Appliance with 2vCPU, 4GB vRAM and default disk sizes. I found with any less RAM I had issues with the database and Autodeploy wouldn’t start properly.

– 3 x ESXi 5 VM’s, each with 2vCPU, 3GB vRAM and 10GB disk. This was enough to test building ESXi hosts with Autodeploy, attach them to vCenter and manage them. I was able to test HA and vMotion among other features. The only nested VM I used was the Nostalgia OVA, I was able to play Prince of Persia during a vMotion, cool!

This pretty much summed up my lab during the study. However, now that I’m studying for the VCAP exams I’m trying to work out the best use of my limited host resources (I have upgraded my RAM to 32GB though).

The question is, what VM’s are the most appropriate and how many? At the moment I only have a Domain Controller, vCenter (full install with UM, etc) and four ESXi guests (three ESXi 5 and one ESXi 4 – I want to test upgrading to 5 using Update Manager).

I thought I’d stand up some VM’s to play with vShield Zones, View, SRM, etc but there are so many products to choose from. Obviously these all won’t be covered by the VCAP exams but I still see benefit in being familiar with them.

What do others out there think? What has worked well in your experience? Bear in mind that I only have 32GB of RAM 🙂

I look forward to hearing your ideas!