Got the new book by Scott Lowe - Mastering VMware vSphere 5

At the last day of VMworld in Copenhagen they finally managed to get a number of copies home of Scott Lowe's new book - Mastering VMware vSphere 5 (they said they would have it by Tuesday at first). I got myself one and I'm really looking forward to reading it. One question, though, is how the book will be able to include best practices and operational experiences when the final product has 'just' come out and most of the book must have been written during the beta? But we'll see.

VMworld Europe 2012 announced - Barcelona

Here at VMworld in Copenhagen, VMware has announced the location for next years 2012 VMworld Europe. It will take place in Barcelona from 16-18 October. I have to give cudos to Copehagen and the Bella Center for hosting two extremely well organised VMworlds (2010 and 2011) but I'm also looking forward to a bit warmer climate next October - providing the boss can be persuaded to buy a ticket.

How to run XenServer 6.0 on vSphere 5 - with nested Windows Server 2008 R2 VM

It is possible to install XenServer 6.0 in a virtual machine on vSphere ESXi 5 and then with a few tweaks you can even run a nested Windows Server 2008 R2 VM on the virtual XenServer 6.0.

To install XenServer 6.0 in a VM, first follow this guide to configure ESXi 5.0 (or watch this youtube video).

One important step is to execute the following command from the console:

echo 'vhv.allow = "TRUE"' >> /etc/vmware/config

Otherwise, configure like the guide. Once the custom VM has been created, to be able to choose ESXi 5 as operating system, go to Edit Settings -> Options -> Guest Operating System choose 'Other' and then choose VMware ESXi 5.x. This will ensure that you won't receive the "HVM is required for this operation" error when trying to boot the win2k8R2 vm (it is possible to change this after the install of XenServer as well).

Download the install .iso from citrix.com 

Mount iso and install XenServer

When done, you will get startup screen as below

Download XenCenter from citrix.com and install

Add the the XenServer to XenCenter

Create a new VM, choose win2k8 R2 64-bit, mount ISO, install.

Done.

Upgrading vCenter v4.1 to v5.0

I just upgraded my home lab vCenter server the other day from v4.1 to v5 and took some screen dumps of the installation process. The steps look fairly familiar compared to earlier versions. At one point in the installation I had an error stating that:

"The Fully Qualified Domain Name cannot be resolved. If you continue the installation, some features might not work correctly"

The reason for this error is that I had not created a reverse lookup on the DNS server. By following this guide, the issue was resolved and installation process could continue without further warnings.

Here are the screen dumps:

It was at this step that the DNS error ocurred. Below image shows how a reverse lookup zone was created on the DNS server.

Configuring iSCSI for vSphere 5

Configuring a software iSCSI initiator for ESXi 5.0 is a relatively simple operation. This quick guide assumes that you have already configured an iSCSI target and published it on the network.

For inspiration, have a look at this VMware KB

Create a new vSwitch (Configuration -> Networking -> Add Networking) and add a VMkernel. Configure it with an IP address. 

Go to Storage adapters and click "Add" to add a software iSCSI adapter if it does not exist already.

Once added, right click the software initiator and choose "properties". 

Go to Network Configuration tab and click "Add".

Choose the vSwitch/VMkernel that you created above.

Go ot Dynamic Discovery tab and click "Add" to add an iSCSI target

You will be prompted to input IP address of the iSCSI target, just leave port 3260 as default unless you have configured it differently on your target.

Go to Configuration -> Storage and click "Add storage". Click DISK/LUN and next. If everything has been done correctly, you be able to see your published iSCSI target and can then add and format it with the new VMFS5 file system, uh lala!

vSphere 5 official release date

Update: 2011.08.25: vSphere has finally been released (as of 2011.08.24)! It can be downloaded from the VMware site.

Update 2011.08.23: Well, vSphere 5 was not released yesterday as rumors would have it - so I guess we'll just have to wait and see. A guess, not completely unreasonable, would be sometime during this week or on the first day of VMworld in the US...

When: The official release date of vSphere 5 - for GA - has been set to Monday 2011.08.22.

I found info about it here and I got the same info from our license vendor.

ESXTOP to the rescue - VM latency

Earlier on I have mostly used ESXTOP for basic troubleshooting reasons such as CPU ready and the like. Last weekend we had a major incident which was caused by a power outage which affected a whole server room. After the power was back on we had a number VMs that was showing very poor performance - as in it took about one hour to log in to Windows. It was quite random which VMs it was. The ESX hosts looked fine. After a bit of troubleshooting the only common denominator was that the slow VMs all resided on the same LUN. When I contacted the storage night duty the response was that there was no issue on the storage system.

I was quite sure that the issue was storage related but I needed some more data. The hosts were running v3.5 so troubleshooting towards storage is not easy.

I started ESXTOP to see if I could find some latency numbers. I found this excellent VMware KB article which pointed me in the right direction.

• For VM latency, start ESXTOP and press 'v' for VM storage related performance counters.
• The press 'f' to modify counters shown, then press 'h', 'i', and 'j' to toggle relevant counters (see screendump 2) - which in this case is latency stats (remember to stretch the window to see all counters)
• What I found was that all affected VMs had massive latency towards the storage system for DAVG/cmd (see screendump 1) of about 700 ms (rule of thumb is that max latency should be about 20 ms). Another important counter is KAVG/cmd which is time commands spend in the VMkernel, the ESX host, (see screendump 3). So there was no latency in the ESX host and long latency towards the storage system.

After pressing the storage guys for a while, they had HP come take a look at it, and it turned out that there was a defect fiber port in the storage system. After this was replaced everything worked fine and latency went back to nearly zero.

In this case, it was only because I had proper latency data from ESXTOP that I could be almost certain that the issue was storage related.

Screendump 1

Screendump 2

Screendump 3