| Backing up and recovering data from virtual machines is easier said than done.
If you use VMs within a Fibre Channel (FC) network, you may have a bit of a problem. FC is a Layer 2 protocol and every VM in a physical server shares a common World Wide Name (WWN). That's like everyone in your firm sharing the same phone number or email address--everyone sees everything. FC host bus adapter (HBA) vendors fixed this problem through N_Port ID Virtualization (NPIV), which lets you assign a different WWN to each VM. However, you have to upgrade all of your HBA drivers. No big deal, right? Wrong. iSCSI and NFS don't have this problem because these protocols are IP based and you can assign different IP addresses to your VMs.
Some of the biggest challenges in data centers revolve around backing up and recovering data in a VM environment. There are so many issues to address I could dedicate a book to the topic. Let's look at a select few.
Backup agent in the guest OS:
| Backup agent in the hypervisor:
While IT vendors tout their technologies, they need to focus more on teaching people how to effectively and seamlessly use their stuff with VMs. Vendors should create interactive communication with their users. It seems to me that the entire world--except for high-tech vendors--is into social networking and Web 2.0.
The journey toward a virtual data center is essential and (dare I say) may even be requisite, but it's fraught with obstacles and challenges. My intent isn't to scare anyone away from implementing VMs, but rather to encourage users to make well-reasoned decisions. Virtualization offers a ton of tactical value to the business and the data center. However, an impulsive, frenzied move toward virtualization can lead to confusion, misinformation and big mistakes. We must leverage knowledge to mitigate risk.