Server virtualization continues to be near the top of the IT top priorities hit list. A recent Goldman Sachs survey of IT spending priorities showed server virtualization in third place followed by closely-related server consolidation in fourth place. And both are closely correlated with the #1 (and not at all surprising) IT spending priority of cost reduction.
But new technologies can also introduce new challenges and complexities, and so it is with server virtualization's relationship to storage. With direct attached storage (DAS) the horse and carriage relationship between servers (CPU horsepower) and storage (data carriage) was clear. Both the physical server and its storage were tightly coupled in a one-to-one relationship (each server and the storage that it "owned"). Even though the introduction of storage area networks (SANs) physically decoupled servers from storage, still each server was physically assigned an allocated piece of the SAN storage infrastructure. So, the relationship between a server and storage was clear even if the assignment of storage could be changed from time to time (which was not possible with DAS). Thus, the distinction between a server as a physical device and a server as an operating system and the software environment that it controlled was irrelevant.
That situation has changed fundamentally with server virtualization with the result that storage has relationships with virtual machines (VMs) instead of physical servers. And VMs themselves are not tied to a particular physical server, but can move around as needed, such as for load balancing and performance reasons. That capability is very powerful and very useful for the management of workloads and application performance. However, at the same time, storage administrators now face challenges in gaining visibility into which VMs are consuming which storage resources. This is necessary to ensure that VMs have the storage that they need to run effectively, to ensure that the overall performance of the server-storage environment meets service level agreements, and to be able to resolve any problems that may arise.
Quite clearly, without the proper software management tools achieving those goals can be very challenging. The problem up until now has been that performing virtual infrastructure discovery and reporting necessary for management of the virtual environment, including storage, was very difficult. And that meant that managing the virtual environment of VMs working with storage was difficult, at best.
EMC's introduction of new automated virtualization-aware Navisphere Manager capabilities for CLARiiON CX4 has changed all that. The company cited an example of a medium-sized VMware environment of 100 VMs spread across 10 ESX servers in which the storage administrator had to view 200 screens for the 10 ESX servers and then record the information on each screen manually to a spreadsheet! Naturally that required hours to complete, but to further compound the problem, the process needed to be repeated to reflect any change to the environment. Obviously, this was a task that overburdened administrators did not look forward to and one that cried out for automation not only to free up time, but also to reduce the possibility for error. But a proper solution should also not inhibit VMware administrators from moving VMs as needed without having to worry about recording and management issues.