The Insidious Nature of Virtual Machine Storage

As virtual machine software continues to proliferate throughout the enterprise, IT managers are taking note of a potentially expensive side effect: increased use of storage.

There are two main issues with virtual machine storage. The first is that over time, virtual machine images tend to grow in size. The second issue is that virtual machine software over time will fragment a disk drive in a way that compromises I/O performance.

Diskeeper hopes to help IT organizations deal with these issues with the release of version 2.0 of its V-locity software for defragmenting disks loaded with images from virtual machine software. The new release adds an IntelliWrite technology that defragments files before they are actually written to the disk, thereby eliminating the need to defragment disks on an ongoing basis, said Michael Materie, director of product management at Diskeeper.

When it comes to virtual machine performance, Materie said maximizing I/O bandwidth is the primary challenge that IT organizations will encounter. In an ideal world, disk defragmentation software for virtual machines might be embedded by the providers of virtual machine software. Of course, it would be nice if the storage vendors would do it themselves, but they seem to have a vested interest in increasing the amount of storage consumed.

It’s still relatively early days for assessing the impact of virtualization on IT infrastructure. But one thing that is for certain is that storage arrays are a finite resource, and the more operating systems that access that storage, the more limited that resource becomes.