VM /ETC

Archive for August, 2009

In order to create customized Windows 2003 and earlier virtual machines (VMs) the Microsoft Sysprep tools need to be added to VMware vCenter (also formerly known as VirtualCenter). Doing so is not a difficult process, but can be a bit confusing if an administrator has never used Sysprep before. Fortunately, VMware has a helpful KB article on the topic that explains where to download the Sysprep files from Microsoft and then where to put the extracted contents of those downloads on the vCenter Server. I’m going to high lite the instructions from VMware for downloading from Microsoft, but then I’ll explain how to get Sysprep from an alternate and arguably easier source – the Windows install CD.

Note that integrating the Sysprep files are still required in all versions of vCenter to customize VMs. This includes vCenter 4 for vSphere. Sysprep is no longer used for Server 2008, however, but VMware has added native customization of Server 2008 VMs in vCenter 4 without adding any additional files.

KB Article 1005593 titled Sysprep file locations and versions not only provides download links and extract to locations but also explains the common symptoms when Sysprep is not installed correctly on vCenter.

• When attempting to customize the deployment of a virtual machine the radio buttons are disabled (greyed out).
• When a virtual machine (VM) is deployed from a Template, you find that the SID is always the same, despite the fact that you chose the option to generate a new SID during Template deployment and guest operating system customization.
• When attempting to create a new virtual machine from a Template in ESX v3.5 you receive the following error message

Warning: Windows customization resources were not found on this server

• Message in the guestcust.log:

deploy doesn’t contain known sysprep files

The KB article explains the cause

Microsoft has a different version of Sysprep for each release and service pack of Windows. According to Microsoft, “You need to use the version of Sysprep specific to the operating system you are deploying”. The differences are not immediately visible in the packaging and documentation of the service packs, so it is necessary to manually investigate.

Use either of the following methods to obtain the appropriate Sysprep files. All instructions in this post assume vCenter has been installed in the default location. Read the rest of this entry »

SQL Server 2008 R2: Virtualization for Databases is a post by Brent Ozar that I had to read slowly and multiple times. Not because it was hard to understand or read, but because the idea it provoked for me gave me the sensation of riding “The Merry Mixer” at the annual traveling amusement park. Ozar’s post explains that SQL Server 2008 R2 introduces the concept of a SQL Server Utility which groups multiple SQL servers as a pool of resources. Ozar explains:

“Looking ahead, Microsoft wants us to start thinking of databases as being less connected to physical servers, and to think of our physical servers as a resource pool.  Imagine if databases were self-contained packages that could be moved from server to server – just like virtual servers can be moved from host to host today.”

The SQL Utility will be managed by a Control Point Server that will collect and monitor configuration and performance data. This server will also facilitate moving SQL databases between Utility members. Apparently this migration of SQL databases will be able to happen live.

SQL 2008 R2 is planned to be released in the first half of 2010.

When I considered how virtual infrastructure (VI) could be impacted by this new technology is when I got a little motion sickness. What if Read the rest of this entry »

In my previous post 730 Days Later I pointed out the default VirtualCenter SSL certificate was only good for 2 years. If the untrusted certificate installed with vCenter and ESX was not replaced by the VI admin problems could arise when connecting with the VI Client or via the ESX 3.X web interface. Now with vSphere the default vCenter 4 and ESX 4 SSL certificate still needs to be changed, but it has been updated and is now good for 10 years giving admins a little more breathing room.

VMware has also updated it’s PDF on how to replace the cert. Be sure to download the new guide for Replacing VirtualCenter Server Certificates. Here is some brief info from the first paragraph of this document:

Certificates are automatically generated when you install vCenter Server and ESX/ESXi. These default certificates are not signed by a commercial certificate authority (CA) and may not provide strong security. You can replace default vCenter Server and ESX/ESXi certificates with certificates signed by a commercial CA.

This Technical Note includes the following topics:
“About vCenter Server Certificates” on page 1
“Pre?Trusting Server Certificates” on page 2
“Certificate Specifications” on page 2
“Certificate Locations” on page 2
“Replacing Default Server Certificates with Certificates Signed by a Commercial CA” on page 2
“Replacing Default Server Certificates with Self?Signed Certificates” on page 5
“Related Publications” on page 8

NOTE   If you have replaced the default vCenter Server or ESX/ESXi host certificates with certificates signed by a commercial CA, you do not need to perform the tasks in this document. You can configure server?certificate verification settings using the vSphere Client. See the Basic System Administration Guide for more information.

The vSphere Basic System Administration Guide can be found here.

VMware also has a couple of KB articles about best practices using SSL keys for communicating with VirtualCenter. Go here or here

An administrator can also decide to turn off the verification of SSL certificates. To do this go to the vCenter Settings from the vSphere Client and disable this feature in the SSL Settings section. This is also explained in the System Administration Guide mentioned previously.

When Microsoft released Server 2008 the Windows Automated Installation Kit (WAIK) was introduced and Sysprep could no longer be used for deploying new servers. This meant that VMware needed to modify vCenter to allow for deploying new VMs from a Server 2008 template. The virtualization community quickly found a work around for the process on vCenter 2.5 and ESX 3.x.

When vSphere was released, it was announced that VMware included the necessary .xml file to customize Server 2008 with vCenter 4, thus meaning that VM customization and 2008 Customization Specifications could be used out of the box without any manual modifications (i.e. adding Sysprep files to the designated vCenter directories). For a walk through of the vSphere Server 2008 deploy from template process with screen shots check out: How to Deploy a Windows 2008 Server From a Template with vSphere

However, in my experience so far creating Server 2008 templates and deploying new VMs the process doesn’t work quite right every time. When I’ve deployed a new Server 2008 VM from the template I’ve experienced an incomplete boot on the new VM. Windows prompts from the install DVD and suggests a recovery is needed. I’ve experienced this recently with 64 bit Server 2008, but I can’t recall if my previous issue was ever on a 32 bit server or not.

Fortunately the same work around for VI 3.5 still works for vSphere as well. Check out the link above for more details, but the basic process is as follows:

1. Build your Server 2008 VM until it’s ready to become a template
2. Before changing it to a template change the operating system type in the “Edit Settings” window to Vista 64 bit
3. Turn the VM into a template
4. Create a customization specification, and / or deploy and customize the new VM.
5. Before booting the new VM change the OS type back to Windows Server 2008

updated 081509 – I had the steps above slightly mixed. Fixed the steps so the OS type change occurs before the VM is converted to template

vSphere has introduced several new features for storage performance enhancement. Most of the new features build on already accepted vSwitch standards and designs. An important example is the new Round Robin MPIO path policy for VMFS LUNs. However, based on what is the common vSwitch design today, the new iSCSI configuration needed for Round Robin multi-pathing may cause some admins to look twice.

I was motivated to write this post by 2 recently published storage vendor documents that both recommend the same basic iSCSI vSwitch with Round Robin MPIO configuration: create a single iSCSI vSwitch, assign 2 physical NICs, and then create as many as 8 VMKernel Portgroups each with their own ip address. The documents I am referring to are:

• NetApp TR-3749 – NetApp and VMware vSphere Storage Best Practices http://media.netapp.com/documents/tr-3749.pdf
• Dell Equallogic CONFIGURING VMWARE VSPHERE SOFTWARE ISCSI WITH DELL EQUALLOGIC PS SERIES STORAGE – http://www.equallogic.com/resourcecenter/assetview.aspx?id=8453

To give a visual of the recommended configuration (in case you are still doing a double take) here are screen shots of the configured vSwitch from: Read the rest of this entry »

This is just a quick follow up post on my blog aggregation rant from the end of June. A couple of constructive ideas for change came out of that exercise, and as a result I have implemented a second RSS feed through feedburner containing just a content summary for VM /ETC posts. The new feed can be subscribed to by any individual or aggregated by other blogs / web sites.

The summary feed is available at http://feeds.feedburner.com/vmetc/summary

You can still get the full posts by subscribing with your favorite RSS reader to http://feeds.feedburner.com/vmetc (or click on the RSS icon in the right column of this site).

It’s inevitable. If you are a virtual infrastructure administrator, architect, or blogger you will eventually talk about VMware VMFS and virtual disk alignment. I’m not going to try to explain the concepts in this post. My goal is to discuss whether to align VMware virtual disks (VMDKs) and what options are available for performing the alignment.

Bottom line is that if you are deploying new VMs from a template you should do so from an aligned master, but VMs created from physical to virtual migrations (P2Vs) present some practical challenges and don’t have to be treated as urgently.

Recommendations

First things first. My interpretation of VMware’s stance on alignment is that they do not advocate aligning every P2V-ed VM to the VMFS due to the administrative effort, disk space requirements, potential VM down time, and in most cases a nominal VM performance increase. On the other hand, it is crystal clear that VMware does recommend always formatting VMFS LUNs with the VI Client and always taking the time to align Gold Image templates so new servers deployed will automatically be aligned.

For reference here’s VMware’s PDF on the topic:

I’ll admit my perspective as a consultant may be a bit different than the normal VI admin. After all, I am mostly involved in the Read the rest of this entry »