However, depending on the type of storage virtualization product being deployed, there can actually be performance increases. Consider a simple environment consisting of JBODs. Since IBM SVC is a caching product, it can actually add RAID functionality and increase performance through the storage virtualization product. Overall, it is generally safe to assume that there will be some performance impact, but question the vendor about performance and evaluate the net effect on your environment.
This is why it's so important for large, scalable enterprises to seriously look at intelligent switch-based or purpose-built appliance-based storage virtualization because the switch-based approach mitigates much of the performance impact found in other deployments.
Check out the entire Storage Virtualization FAQ guide.
This was first published in August 2007