Archive for February, 2011

Phantom Snapshots: Resolving Orphaned Snapshot Issues

February 18, 2011 Leave a comment

Recently, we had an issue with Phantom Snapshots. Basically, we had a VM with multiple VMDK files (vmname_01-000001.vmdk) and by multiple, I mean 26 snapshot vmdk files per VM HDD. It was quite a nightmare and was taking up a lot of space on our datastore. Unfortunately, they were not showing up in snapshot manager, nor showing up on our morning snapshot report, so they went unnoticed. Luckily, we caught these and were able to get the issues resolved.

The first problem was we were not able to ‘Delete the snapshot’ from snapshot manager, because it wasn’t there. The simple fix for that was to clone the machine during off hours. The cloning process consolidates the snapshots, and leaves only 1 VMDK file per VM HDD. Once the Line of Business confirmed the new machine was functional, I proceeded to delete the old VM thinking my problems were over. Boy was I wrong.

The delete ran perfectly fine, yet when I went back to determine if the files had actually been removed, there were still a few VMDK files left that weren’t deleted. Every time I tried to delete them from the datastore I received an error. Quick trip to the blogs and the VMware Community Forums, and I found I was not alone. Others had experienced this and the fix was to restart the hostd services on the owning ESX host of the VM, or reboot that host. Problem was, I didn’t exactly note which host this VM was on last.

Luckily we have a daily health report that comes out which list all the major task performed in the past 24 hours, so my delete was listed, along with which host I deleted it from. I proceeded to evacuate the host of all VMs with the help of DRS and placed the host in maintenance mode. I decide a reboot would be the simplest solution and anytime you get the chance to reboot a host, it’s never a bad thing in my book.

Post reboot, files were able to be deleted with no issues and all was well in the world on VMware here in my data center. I hope having all this information in one spot will help future admins with this issue. Having files eat up disk space is never a good thing and being able to resolve it quickly is a big help. If you run into this problem in the future, the steps to fix are:

  • Clone your VM to consolidate snapshots
  • Note which ESX/ESXi Host your problem VM is running on
  • Delete the problem VM from inventory
  • Evacuate other VMs from identified ESX/ESXi Host
  • Restart hostd services or Reboot Host
  • Delete leftover VMDK files from datastore
  • Have a Coke and a Smile
Categories: VMware Tags: , , , ,

VMware Release vSphere 4.1 Update 1

February 11, 2011 Leave a comment

Many of you noticed your VUM alerting you to the fact that VMware released Update 1 for vSphere 4.1. The amount of new items is pretty short and routine. They include the following updates to ESX/ESXi:

  • Support for up to 160 Logical Processors
  • Additional Drivers Support
  • Enablement of Intel Trusted Execution Technology (TXT) for ESXi Only
  • Additional Guest OS Support

vCenter also received some new items and they include:

  • Additional Guest OS Customization Support
  • Additional vCenter Server Database Support

The interesting thing here isn’t the fact that there is any amazing new features. What’s crazy is that this could be potentially the last update that an ESX host ever receives. I’d suspect the next update (4.2) will be released for ESXi only, as VMware has previously announced 4.1 would be the last ESX update.

Categories: VMware Tags: , , , , , ,

Citrix XenClient 1.0 SP1: First Thoughts

February 2, 2011 Leave a comment

I was lucky enough to receive a new HP EliteBook 8440p laptop last week and quickly realized it was a vPro machine. First thing that popped into my mind was ‘Is this on the HCL for XenClient?’ Sure enough it was, so I proceeded to download, format my laptop, install XenClient, and explore this new technology. I have been running this for almost two weeks now. Here are my thoughts so far.

First, for those not familiar with XenClient, it is a Type 1 Hypervisor from Citrix that runs directly on your laptop. I wont go into too many details as many people have written on it, including myself. Along with most people, my first post discussed how it seemed that this product was rushed when it was released at 1.0. Have things changed with SP1? That’s what I wanted to find out.


Installation was fairly simple. I downloaded the ISO from Citrix’s website, burned and was off. Well, or so I thought. First error I got was about my BIOS not being configured properly with VT. Reboot and into the BIOS I go to correct it. Once that was fixed however, things went off without a hitch. Installation was a simple text-based installer similar to any Linux-based Distro.

Getting Started:

For the initial installation, I decided to forgo Synchronizer and just install XenClient and create VMs locally. I started off creating a Windows 7 x64 Professional box to house my work environment. Everything ran smoothly. The only caveat is peripheral devices such as Webcam and Fingerprint Scanner need to be added to the VM post boot. Webcam works fine, however FP scanner is still giving me some issues, but its more on the Windows side, so I need to tinker with the drivers some more. XenClient itself recognizes the FP Scanner.

Next I built another Win7 VM for personal use. Again, no issues. Then I decided I wanted to play outside of the box a bit. Currently, only 4 Guest OSes are supported: Win7 32bit, Win7 64bit, Win Vista SP2 32bit, and WinXP SP3 32bit. I’m sure Citrix is planning on expanding the support OSes, but until then, anything outside of that is unsupported. Well, I figured it couldn’t hurt to see what was capable.

I decided to build a Fedora 14 x64 Desktop Edition VM. Things went rather smoothly, aside from the large orange error triangle over the VM icon due to a lack of tools being installed. System runs fine and finds most of my items. The only thing not functional is the webcam and fingerprint reader, but issues are to be expected with unsupported technology. That said, none of the issues I found were major showstoppers. The VM runs great and I can certainly use it on a day-to-day basis. I hope this is a sign that Linux support is on the way since they are very close as it sits now with XenClient 1.0 SP1.

Day to Day Use:

Since I didn’t have as much time to complete this article in the time I wanted to, due to work and personal obligations, it did give me much longer hands on time with my XenClient laptop prior to publishing this. All and all this is a very viable solution. I did have to upgrade my memory as the standard 2GB just wasn’t enough. After installing 8GB of RAM, this became a lot more viable day-to-day product. I am now able to run 3 VMs at once with no issues. This allows me to run my work image, which consist of a Windows 7 VM, my personal desktop image, the Fedora 14 Desktop, as well as a test VM, usually an XP or Win7 machine, to install new products and lab stuff out as needed.

Swapping between VMs is a simple as pressing Ctrl + the number key corresponding to the proper VM. Pressing Ctrl+0 allows me to go back to the XenClient landing area and select between my VMs, modify them, or edit XenClient settings.


Overall performance of the VMs were excellent. Keep in mind my day-to-day work involves no crazy 3D graphics, or insane amount of CPU intensive applications. Things certainly perform up to my expectations for my day-to-day work. Office 2010 runs great on my Windows 7 VMs. Browsing is fast and responsive, and blogging works with no issues. I don’t notice any stuttering with watching videos online or listening to music.

On my Windows 7 work VM, all of my day-to-day items, such as vSphere Client, Office 2010 Suite, AD and Windows Admin tools, as well as all the other items I run throughout the day perform perfectly. I did notice if I enabled the ‘Experimental Feature’ for 3D Graphics Support, the Windows Experience Index went from a 1.0 to a 4.2. If someone performed a more graphically intensive task, this would certainly need to be a feature that they enable.

Issues and Complaints:

While overall I am impressed with XenClient, there are some issues. As I said in my last article, it seems sketchy that most of the good features that one would expect in this current technological climate with virtualization are all labeled ‘Experimental.’  The limited hardware and guest OS support does create few options and shrink the audience of users for this product. Also, the fact that the maximum amount of memory I can devote to a VM is capped at 3GB, which can be a hinderance for VMs with a heavier workload. Another issues I noticed was whenever a secondary VM shutdowns, the primary VM you are using flickers in an out for about 5-10 seconds. Things return to normal, but it is a bit of an annoyance, and caused some panic the first few times it happened. All and all minor issues, but things could certainly be more polished and less ‘experimental.’


After running XenClient for a week, I decided to install Synchronizer and give it a shot. The idea behind Synchronizer is a good one, but I think the execution is a bit off. It’s nice to be able to sync your VMs with a central store, but it seems more like a backup option than anything. Maybe its uses will continue to grow, and more features will be added. I also find it inconvenient that you must build a VM inside XenClient and then sync it up to the Synchronizer, and there is no way around that. It seems like I should be able to P2V a box and dump it right to Synchronizer. Maybe Citrix will add this feature, and hopefully add it soon.


All and all I think XenClient is a great product. It is what Citrix hyped it up to be? No. I think they rushed a product out just to have the bragging rights of being the first major Type I hypervisor on the market. In its current state, I see this as more of a tool that IT professionals, or tech savvy users will fully embrace and use. It certainly isn’t ready for primetime as a Virtual Desktop solution and is definitely more of a niche product in this stage. I hope Citrix continues to grow this product and increase its capabilities, such as more OS support, greater hardware adoption, and increased features, as well as expand the scope of the target audience. Synchronizer could use a bit more thought, work and polish as well. I think this product and technology has a lot of potential, and I do think its something I will continue to use and hopefully continue to upgrade often (hint hint Citrix 😉 )

A New Look and a Thank You

February 1, 2011 Leave a comment

Well, its been about a year since I created Virtual Blocks and things have picked up around here. I decided to step things up and add a new theme that has a cleaner, and more professional look. I also plan on trying to knock out at least one post a week. I’ve got a couple of items half-written now, including a write-up on my impressions of XenClient based on my recent experience with it. I hope to publish that article this week.

All and all I wanted to thank all my readers who visit my site. I started this blog as a place to put my thoughts and experiences based on my day-to-day so I’d have a place to go back and refer to them. I’m glad to see that to this day, that people have looks at my site almost 1,000 times and have hopefully benefited from my information.

Thanks again for all the support.