Wednesday, July 8, 2009

As the virtual machine partitions are resized each windows virtual machine is then 64k block aligned. VMware states that VMFS partitions that align to 64KB track

boundaries result in reduced latency and increased throughput. Partition alignment on both physical machines and VMware VMFS partitions prevents performance I/O degradation due to unaligned tracks. vOptimizer simply makes it easier to get and stay there.

vOptimizer Pro provides many of the benefits of thin provisioning without the downsides. There is a lack of transparency with thin provisioning, meaning that both ESX and the virtual machine have no idea how much storage they have allocated to them. Despite warning to the contrary the concern with Thin Provisioning, especially in virtual environments is that you might accidentally commit more storage than is really available and not catch all the available warnings as that space evaporates.

If this happens, a shared production data store could run completely out of space. All VMs trying to add more data would fail resulting in catastrophic business outages.  There is always a higher risk of running out of disk space that would result in VM's crashing. Finally the provisioning in VMware is upfront value, volumes cannot shrink, space created by deleted files that cannot be reclaimed.

For now it is a trade-off between thin provisioning and using a tool like vOptimizer Pro. If your current storage solution does not provide thin provisioning then adding this software is an inexpensive, no brainer alternative. Deciding on whether to use vOptimizer Pro or a thin provisioning solution also depends on whether customers are trying to reclaim existing wasted VM storage or trying to prevent more storage over-allocations as they create new VMs from now on.

In the future vOptimizer Pro will become thin aware and it will actually enhance thin provisioned systems by offering reclamation of space made available because of deleted files as well as the ability to move superfluous, junk windows files.

vOptimizer Pro 2.2 extends that capability to include ROI Scanning – it alerts customers as to just how much over-allocated storage they are wasting and how much it is really costing them.  You specify storage cost and desired free space to ensure accurate estimates are reported.

This allows a customer to determine how much storage is being over-allocated. The product can then provide an estimate of savings gained from reclamation and provide a report on the details. This allows the business to decide when and to what level the actual optimization be performed.

In addition to the enhanced scanning and reporting the product now features support for 32-bit and 64-bit versions of Microsoft Vista and Microsoft Windows 2008. Also the browsing for virtual machines to be scanned has improved making reclamation an easier task. Finally the 2.2 release also supports VMware’s latest release; vSphere.

Another interesting aspect of vOptimizer Pro is its ability to locate VMs that are running dangerously low on storage and then prevent outages. Customers could run regularly scheduled maintenance jobs that ensure volatile VMs always have sufficient free space.

Once these machines are identified vOptimizer automatically adjusts the size of the files associated with those virtual machines. This is in essence a repartition of the virtual drive so the VM does need to be shut down while this happens but the effect is a real space savings that the operating system recognizes as opposed to thin provisioning that fools the operating system.

For example, Vizioncore cites one recent customer example One recent customer discovered that they had 67+ TB wasted in one data center. Their virtual storage was 86% empty and they were wasting hundreds of thousands of dollars (close to $1M). This customer knew that they had significantly over-allocated VM storage, but had absolutely no idea how bad the situation really was until we showed them.