Improving Storage Utilization: Driving Down Cost and Complexity
- Published on November 19, 2007
How Do You Define Storage Utilization?
It’s fair to say that companies who feel they have high levels of storage utilization probably haven’t run the numbers lately. They may look at how full their disk arrays are and assume that because they’re at 70 or 80 percent of capacity their storage utilization is acceptable. But simply reviewing overall disk capacity usage fails to address what is being stored.
The majority of storage devices contain a large percentage of data that is of little or no immediate business value. Much of it may be non-business-related files such as MP3s. More often, many of the files may be duplicates, old, or rarely accessed. Of the files that are clearly business-related, many may not have been used in the last 30, 60, or 90 days. So a better storage utilization question would be, what percentage of capacity is really being used for files that have current or ongoing business value?
When companies analyze storage utilization from this standpoint, the results are usually surprising, if not shocking. One financial institution I spoke with recently determined after a careful analysis that its actual storage utilization was only 8 percent. Other companies confirmed estimates in the single digits.
Virtualization Enables Storage Pooling for Better Utilization
The ability to pool storage into logical volumes has been around for some time. And yet, the technology is still somewhat underutilized. Consider a situation in which a particular disk array (A) is only 50 percent full. If an application that uses another array (B) needs more storage capacity, but it can’t get any from (A), the administrator has to consider buying more capacity while the array (A) sits half-empty.
Storage virtualization helps improve the utilization problem outlined above by enabling administrators to pool all storage into logical groups that can be reallocated quickly or in real-time based on demand. The best virtualization software can do this across any storage array from a variety of vendors, running under a variety of operating systems, from a single management interface.
When storage resources are virtualized, they appear to administrators as a single resource. For example, two 72GB drives can be combined to create a 144GB drive. Data can be moved transparently across vendors and operating systems to utilize available capacity. Storage management tools also enable IT shops to classify data by age or type so that less valuable or less current data can be moved automatically to less costly storage (more about this later). Storage utilization improves. Capital costs shrink. And there’s more: using storage virtualization, new tools enable you to migrate data between operating systems – from AIX to Linux, for example, or from Linux to Solaris.
Not only does this storage pooling improve storage utilization, but administrators instantly become more productive and can now spend more time on other tasks such as building business applications. They no longer need to be proficient in multiple storage technologies. IT departments are free to choose among vendors to find the best price point with no concern about gaining new proficiencies.
Moving Data Between Classes of Storage Based on Importance Improves Utilization
Another useful response to the utilization problem has been to segregate data into multiple tiers according to the cost of hardware, freeing up expensive high-performance storage by migrating older, less-used data to more affordable arrays (that you may already have). This data migration can be done based on the age, size, owner or other attributes of the file. It can be done in reverse if a file that was once unimportant suddenly becomes very important.
Let’s recap the benefits of storage management solutions:
1. Reduced or stabilized head count. Gartner reports that personnel costs for administration average seven times hardware costs. With storage virtualization, you don’t need an administrator for every vendor’s hardware. All administrators only need proficiency in a single interface – the volume manager that virtualizes all storage resources. They become far more productive.
2. Reduced capital expense. Virtualization enables administrators to exploit all available space, reducing the need to buy hardware. Keep in mind that I’m not suggesting you can put off purchasing new hardware forever. However, with the rapidly dropping cost of storage, deferring a hardware purchase for even a few months could result in significant savings.
3. Simplification of management. IT managers and administrators no longer have to think in terms of multiple vendors and operating systems, or of buying from a single vendor to retain homogeneity while missing opportunities to buy less expensive hardware from other vendors. A single storage management interface eases their management challenge.
The Bonus: Simple, Cost-Effective Data Replication and Migration
In addition to these savings and efficiencies, storage management solutions can eliminate other pain points and improve the lives of IT administrators in a number of important ways.
Describing all those benefits is beyond the scope of this article, but there are several benefits worth highlighting. Let’s focus on one area: replication of data.
Heterogeneous storage management tools can replicate data over large distances to secondary (or remote) sites more efficiently, greatly reducing (or eliminating) the threat of data loss and downtime caused by a disaster at the primary site. This capability is fast and efficient when data needs to be recovered after a disaster. Because this replication can be done from a high-end array to a low-cost array, the utilization of expensive storage arrays is improved and the capital cost of replication is driven down.
Another capability of some storage management solutions is the ability to migrate data for consolidation purposes, or when switching operating systems. Enabling better migration allows administrators to better utilize server resources as well.
Moving Toward Increased Storage Utilization
If your organization hasn’t analyzed its storage utilization, it will be worth asking some basic questions:
- How much storage have I really got? In large data centers and IT departments, it may be difficult to know exactly how many storage devices exist, and what their capacities are.
- How much of that capacity – on a device-by-device basis – is actually filled with data?
- How much of that data is actually important and has been accessed (in the last 30, 60, or 90 days)?
This information will tell you how much total unutilized space could be available. It will enable you to identify storage resources that could be pooled into logical groups and virtualized. It will also enable you to set up a plan for migrating aging data to less costly storage or even archiving it.
At the end of this process, you will have a clear picture of your storage capacity, of your true storage utilization. Storage management tools can then enable you to carve up capacity in a highly efficient way to drive up storage utilization and save you time, complexity, administrative costs, and capital cost.
Robert Soderbery is vice president of product management, marketing, and delivery for Veritas Software. He oversees product management, marketing, and delivery for the storage and server management group. Soderbery holds a BSEE from California Institute of Technology and an MSEE from Stanford University.