Virtualization Pro

July 31, 2009  2:22 PM

Using Storage VMotion to keep critical servers up when shared storage is down

Eric Siebert Eric Siebert Profile: Eric Siebert

What a great tool Storage VMotion is. I may not use it every day, but when certain situations arise I really appreciate having this feature available.

The other night our storage area network (SAN) admininstrators shut down both of our SANs so they could do a microcode upgrade. Part of this process involved shutting down all of our production virtual machines (VMs) that were on shared storage before the SAN was shut down.

But there are certain servers that you want to have available at all times. In my work this includes at least one DNS and Active Directory server as well as our VPN authentication server. Because these VMs are all on shared storage I decided to use Storage VMotion to move them temporarily to local storage so they would be available while the SAN was down. With Storage VMotion I was able to do this while all the VMs were powered on with no interruption to service.

What Storage VMotion is and how it works

Introduced with VMware ESX 3.5 and vCenter Server 2.5, Storage VMotion allows you to move VMs from one storage data store to another while the VM is running. The difference between VMotion and Storage VMotion is that VMotion simply moves a VM from one ESX host to another but keeps the storage location of the VM the same; Storage VMotion changes the storage location of the virtual machine while it is running and moves it to another data store on the same ESX host. The source and destination data stores can include any storage volume that is configured on an ESX host, which includes local and shared storage. The magic behind Storage VMotion involves several behind-the-scenes steps, which are outlined below: Continued »

July 31, 2009  2:06 PM

Good experiences with vSphere 4.0, vShield Zones VMware support

Eric Siebert Eric Siebert Profile: Eric Siebert

Support and customer service are two areas that will make or break any company. Providing good support and customer service will ensure that a business keeps is customers satisfied so they continue to use the company’s product and do not consider switching to a competitor’s product.

Since I have recently had several good experiences with VMware support I thought I would pass them along as I feel VMware is doing a good job in this area. I haven’t used VMware support in years; previously I’ve had bad experiences with using Hewlett-Packard for technical support for VMware product issues, but we’ve recently switched to using VMware directly for our support instead of HP. So when I ran into several issues when testing the new vShield Zones product I thought I would give VMware support a try again and see what kind of experience I would have.

VMware vSphere 4.0 licensing

My first support issue was with vSphere licensing. I tried VMware’s online licensing support. My problem was that I was not seeing my Enterprise Plus licenses when logging in with my VMware account on VMware’s website. I could see my vCenter Server and vSphere licenses but not my Enterprise Plus licenses, which I suspect were showing on another VMware account that was created by the person who does the license renewals for us.

Continued »

July 22, 2009  2:26 PM

VMware ESX Web access in vSphere

Eric Siebert Eric Siebert Profile: Eric Siebert

With VMware Infrastructure 3, Web access was enabled by default. VMware chose to disable it in vSphere for security purposes. If you access an ESX 4 host with a Web browser you will see the default welcome page but if you click the log-in link you will get a 503 Service Unavailable error message.

This only affects ESX hosts (VMware vCenter Server has this enabled by default; ESXi does not have a Web access user interface (UI) to manage the host and virtual machines).

There is a tech note that describes the process for enabling this feature in ESX 4.0, but before you go ahead and do this you should ask yourself if you really need this feature enabled on all your hosts. VMware disabled this feature for a reason — Web based access methods are inherently insecure and are subject to numerous vulnerabilities that could potentially compromise your VMs and hosts.

The Web admin UI is very limited as you can only administer guest VMs and not host servers. Leaving it disabled removes a potential attack vector for your ESX hosts and makes them more secure. This is also true of other configuration settings that are disabled by default in ESX such as root access using SSH.

The first thing many administrators do is enable this because it is easier than setting up another user account and using su or sudo. So resist the urge to enable web access and utilize the vSphere client instead. If you must use web access for a specific reason only enable it on the hosts that need it. If you are using a vCenter Server use the web access on vCenter instead and use the roles and permissions built into it for additional security. By leaving vSphere web access disabled you are helping to make your ESX hosts and your whole virtual environment more secure.

July 13, 2009  9:27 PM

Monitoring vSphere adoption: A forum moderator’s perspective

Texiwill Edward Haletky Profile: Texiwill

As an active moderator and VMware Communities Guru, I’m in a unique position to see the level of vSphere adoption from an interesting vantage point — topic activity in the forums.

Take one morning’s statistics from this past week:

  • 3 pages of new VMware vSphere Forum Posts vs 1.5 pages of VMware ESX 3.5 Forum Posts.
  • VMware ESX 3.5 Forum posts used to be around 3 pages
  • The majority of VMware vSphere Forum Posts that dealt with ESX 4 vs ESXi 4 was in favor of ESXi 4 by a wide margin (I did not actually count posts but noticed there were more ESXi posts than ESX posts in those 3 pages)

So using this as a rough measurement and in a completely unscientific way, we do see that VMware vSphere is being investigated for use at least by those activie within the VMware community forums. The same thing happened when ESX v3.5 was released, and over time ESX 3.0 community posts dropped to less than a dozen per day. (I say per day because I review the vSphere, ESX 3.5, and ESX 3.0 communities once about every 24 hours give or take an hour or so.)

Given the types of questions, it looks like two things are happening:

  • VMware vSphere is being investigated
  • VMware ESXi 4 is the packaging of choice

The second item could be because many people believe that when the next version of ESX comes out, it won’t have a service console, and these users want to get a head start on the adjustment.

What we do not know from this type of adoption measurement is whether these are adoptions for use within production, enthusiasts, or testing within lab environments.

What we do know is that the increase in volume and the drop in ESX v3.5 forum posts is that vSphere is definitely gaining traction. This is not surprising, but what is to me is that ESXi 4 has a constant flow of posts while ESX 4 does not. This will shift the security model people employ to protect virtualization hosts as well.

July 9, 2009  3:06 PM

Now accepting Best of VMworld nominations

HannahDrake Hannah Drake Profile: HannahDrake

We are now accepting nominations for the 2009 Best of VMworld awards. Judges will visit contenders’ booths at VMworld 2009, and winners will be announced at the VMworld show (more information to follow). Products must be from a company exhibiting at VMworld 2009. In addition to the other awards, a single Best of Show award will be given at the judges’ discretion.

Categories are as follows:

  • Data protection and business continuity software
  • Security and virtualization
  • Virtualization management
  • Virtualization infrastructure
  • Desktop virtualization
  • Cloud computing technologies
  • New technology
  • Best of show (*No user-submitted entries for this category)

Deadline for nominations is July 31, 2009.

Nominate a product for this year’s Best of VMworld awards here.

July 9, 2009  2:29 PM

Will Google save VMware from Novell-like fate?

Eric Siebert Eric Siebert Profile: Eric Siebert

There has been some talk recently about the possibility of VMware becoming the next Novell and fading away into obscurity due to Microsoft entering the virtualization arena. But has anyone noticed that Google is slowly invading many of Microsoft’s territories and doing it better than Microsoft at a cheaper price?

The recent announcement that Google is developing its own Google Chrome operating system to go along with the Google Chrome Web browser is a direct threat to Microsoft’s core business. Google is competing with more and more Microsoft products and most of its products are available to consumers for free. Google has email, a Web browser, documents, mapping, photo and drawing applications and much more. Will Google eventually topple Microsoft and beat them at Microsoft’s game, forcing Microsoft into obscurity as Microsoft has with companies like Novell and Netscape? Continued »

July 8, 2009  3:20 PM

Scheduling virtual CPUs

Eric Siebert Eric Siebert Profile: Eric Siebert

Recently someone asked me what VMware scheduling is, so I thought I would cover that in this blog post. Scheduling, or virtual CPU scheduling, happens behind the scenes and is not a very visible component of virtualization, but is absolutely critical for virtualization to work properly. You should have at least a basic understanding of how it works so you understand how it impacts virtual machine (VM) performance and what to look for when troubleshooting malfunctions.

Scheduling 101

The scheduler is a component of the VMkernel that schedules requests for the virtual CPUs assigned to virtual machines to the physical CPUs of the host server. Whenever a virtual machine (VM) uses its virtual CPU, the VMkernel has to find a free physical CPU (or core) for the VM to use. On a typical host server, the number of virtual CPUs usually outnumbers the number of physical CPUs, so the VMs are all competing to use the limited number of physical CPUs that the host has. The scheduler’s job is to find CPU time for all the VMs that are requesting it and to do it in a balanced way, so performance for any one VM does not suffer. This is not always an easy task, especially when VMs are assigned multiple virtual CPUs (virtual symmetric multiprocessing, or vSMP) as this further complicates the scheduling.

Continued »

July 1, 2009  3:13 PM

The votes are in: Favorite vSphere enhancements

Eric Siebert Eric Siebert Profile: Eric Siebert

Now that users have started using vSphere, I wanted to know which new technologies in the latest ESX platform release are most popular. I ran two polls on my website, and the survey results are in: Thin provisioning is the favorite new major enhancement and alarm improvements are the favorite smaller enhancement. Both features existed in VMware Infrastructure 3 (VI3) but were very limited and difficult to use.

In VI3, thin provisioning could only be used when creating virtual disks via the command-line interface, but in vSphere it is fully integrated into the vSphere client, which makes is much easier to use. Additionally, new alarms and reporting helps manage your thin-disk usage.

Continued »

July 1, 2009  2:26 PM

Virtualizing Microsoft SQL? Consider per-processor licensing

Rick Vanover Rick Vanover Profile: Rick Vanover

In a recent tip, I outlined situations where it does not make sense to have SQL or Exchange virtualized. The bottom line is that licencing depends on many factors, and you need to consider licencing when virtualizing such applications or you could end up spending more money than necessary. One point worth noting that is not in the tip is if you opt to license Microsoft SQL Server per-processor, it may carry additional benefits.

Continued »

June 30, 2009  9:03 PM

Three ways to kill a frozen vSphere ESXi host virtual machine

Eric Siebert Eric Siebert Profile: Eric Siebert

At some point, you may need to know how to kill a stuck or frozen VMware vSphere 4.0 ESXi host virtual machine when the traditional power controls do not work. As with VMware ESX, there are several methods, which I covered in a previous post, killing a virtual machine (VM) on a VMware ESX host in vSphere.

The methods for ESXi are very similar to that of ESX, but the execution is different as ESXi doesn’t have a service console like ESX’s. The methods below are listed in order of usage preference, beginning with using normal VM commands and ending with a brute force method.

Method 1: Use the vmware-cmd command in the vSphere command-line interface (CLI) Continued »

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