Friday, May 28, 2010

VDI: The next big storage challenge

May 28, 2010 – Virtual server administrators and their storage brethren know full well that to reap all the benefits of a virtualized environment you need to clear a lot of storage hurdles. And InfoStor readers know that there are plenty of storage products and strategies to get the job done, whether the challenge is performance or data protection.

But fine tuning your storage environment to maximize your virtual server environment may seem like a walk in the park compared to performing the same task in a virtual desktop infrastructure (VDI).

As openBench Labs CTO Jack Fegreus put it in a VDI-related lab review we recently posted (see below):

“IT may well find that the distributed computing sea change in server virtualization will be dwarfed by a rapidly growing tsunami in virtualized desktops. On the client side, the corporate pool of desktop and laptop PCs has long been the uncharted sea of IT. And the sheer number of client devices makes the over-provisioning of CPU and storage resources for these systems a huge capital expense.”

Gartner estimates that, so far, only about 500,000 desktops are running on VMs – a fraction of the $150 billion PC market. However, Gartner predicts that IT will migrate 30% of its installed based of PCs to VMs by 2014. If that happens, the ranks of VMs running client systems will swell to more than 18 million.

According to Fegreus, best practices call for deploying desktop VMs four to eight times more densely than server VMs (which is possible because of the sporadic nature of desktop usage). This is great in the context of cost savings, but dense deployment also leads to resource utilization storms involving I/O, storage, CPU and memory resources.

“What makes storage so important are the inextricable links to the capital and operational expenses that IT must restructure to maximize the ROI of a VDI initiative,” according to Fegreus.

To explore storage issues in a VDI context, openBench Labs set up a test scenario with off-the-shelf servers, a VMware ESX 4 hypervisor with lots of other VMware software, and backup software from Veeam, all anchored by a Fibre Channel disk array from Xiotech.

Check out the full lab review: “VDI: For virtual desktops, latency matters.”
http://www.infostor.com/index/articles/display/5907788482/articles/infostor/openbench-lab-review/2010/may-2010/vdi_-for_virtual_desktops.html

Hardly light reading for the holiday weekend, but if virtual desktops are in your future it’s worth the click.

1 comment:

VV the Gatt said...

Clones are not needed !

You can also, instead of cloning your desktop VMs, stream the disk to them.

I used to do that with HP Image Manager.
Streaming a 10GB XP image to 1000 VMs would then use only... 10GB of Image space.
You need a little temporary space (really temporary), let's say a maximum of 2GB per VM, plus the virtual memory size (from the host perspective, not from the guest perspective). 3 to 4GB of disk space per VM are a good approximation.
Note that my VMs are configured not to have any "hard disk drive". They PXE boot to HP Image Manager server.
It's fast and efficient.
And when I need to update the image on 1000 VMs, I just do it once, on the reference image, and it gets populated to all the VMs as soon as my updated virtual disk image is shared and the guest VMs are rebooted.

As for user data, I use folder redirection and roaming profiles.

Very efficient indeed, I would not use VDI without an OS/Disk streaming solution.