If you're looking to defragment SANs (Storage Area Networks) or VMs (virtual machines), you're on the right track. But, there are things you need to be aware of. Defragmenting SAN attached storage and VMs can require planning, implementation, and configuration that is generally unnecessary with direct attached storage (DAS). 

For example, what do you do if you use Thin Provisioning? What about Linked Clones? Does defrag still help if your multipathing? 

The paper sets out to address many considerations and technologies in modern storage infrastructures, and offers "best practices" guidance based on our decades of experience working with many of the largest companies in the world to help them maximize their system's performance and reliability.  

Click on the image below to read the paper.

It makes for fascinating reading on a Saturday night. Just get the fireplace firing, grab some milk and cookies, get a warm blanket and curl up in bed (or on the couch) and enjoy! ;-)