No scheduling makes for a very visible disk I/O bottleneck in a virtual environment

While the ability to only defragment when a computer is "idle" - with something like PerfectDisk 2008's StealthPatrol automatic background processing - may work in certain environments such as workstations or laptops, it very often does not work in production server environments. This is because there is no guarantee that a busy production server will have sufficient "idle" resources for defragmentation to run effectively. And this is particularly true in virtual environments, where it can actually cause performance issues for all of your virtual machines.

A virtual machine is only aware of disk activity as seen by that virtual machine. A virtual machine isn't aware of disk activity generated by other virtual machines. If all of your virtual machines think that they are "idle" and begin defragmenting, the increased I/O activity can quickly overload the disk hosting the virtual machines and cause performance issues for all of the virtual machines.

PerfectDisk 2008's ability to schedule defragmentation to occur at a defined time provides system managers the ability to manage disk I/O so that defragmenting of virtual machines doesn't overload the I/O capacity of the host drive. A group of virtual machines can be scheduled to defragment at a specific time and another group of virtual machines can be scheduled to defragment at a different time.

This is easily accomplished using the PerfectDisk 2008 Command Center management console. You can define your own custom groups and assign a computer to that group or link to an existing Active Directory OU. A schedule can be assigned to individual computers or a group of computers or to the linked OU. You can also configure PerfectDisk 2008 to run at a low CPU priority and to throttle Disk I/O usage. When PerfectDisk 2008 defragments the virtual machine, it will do so with the least amount of system resource impact on the virtual machine.

This is just one of the reasons we are seeing record sales for PerfectDisk 2008 Server. By limiting the number of virtual machines that are defragmenting at any one time, you limit the I/O impact on the host drive and preserve performance for all of your virtual machines. You only get this with PerfectDisk.

And that's easy to see.