Calculating the Benefits of File Virtualization

IT often reacts to data growth by adding more storage devices. There’s a better way.

by Nigel Burmeister

The rapid growth in file-based information is placing additional strain on IT organizations when it comes to managing file-based storage. While information is being created at an unprecedented rate, regulatory and business needs require the preservation of more information for longer periods of time. To meet capacity demands, the most common solution is to add new storage devices. This solves the short-term need, but ultimately creates new -- and expensive -- problems by ramping up infrastructure complexity and operational costs.

In a series of interviews with senior IT executives at U.S. and European enterprises for a project commissioned by F5 Networks , IDC found that companies are increasing their file-based storage by 40-120 percent a year, a growth rate that has direct economic impact on enterprises in a number of ways:

  • Dispersed file servers often cause utilization rates to sink to less than 15 percent
  • More resources are being allocated to make unneeded copies of older, unchanging files, which are often 80-90 percent of all files being backed up
  • Growing management complexity inhibits employee collaboration by preventing the information sharing across groups or geographies
  • Efforts to migrate and consolidate data from even a limited number of file servers onto larger, more centralized NAS systems can often take six months to a year
  • Ongoing integration and tuning of independent file structures as data grows and organizations change lead to downtime and severe, ongoing disruptions, driving down employee productivity and increasing the burden on IT staff

(For details about the report, see Note 1; the report is available at

Quantifiable Savings from File Virtualization

One solution that is helping organizations better manage file-based information and reduce costs is network-based file virtualization. This technology decouples the logical access to data from the physical location of that data and enables the enforcement of powerful intelligent storage management policies. This eliminates the downtime typically associated with common storage management tasks, and simplifies the way file data is accessed and managed. As a result, measurable savings can be realized.

In the IDC project, companies that had deployed file virtualization stated they could:

  • Rapidly and non-disruptively migrate data from file servers to more scalable NAS systems (cutting migration times by up to 90 percent)
  • Automate movement of data to lower-cost tiers of storage based on preset policies (reducing spending on disk capacity by 50-80 percent)
  • Reduce resources set aside for backup (cutting tape consumption and backup times by up to 80 percent)

These statistics are compelling. Let’s take a closer look at some of the ways companies are addressing the economic impact of rapid file-base information growth.

Savings from Tiered Storage

A tiered storage strategy enables companies to augment their expensive, high-end storage with more cost-effective technologies such as serial ATA (SATA) and move non-critical business data to those lower-cost alternatives. Other organizations want to reduce backup times and lower backup infrastructure costs by reducing the amount of unchanging, or non-business-critical data that is backed up on a regular basis.

File virtualization enables storage managers to deploy tiers of file storage with adaptive, automated information lifecycle management (ILM) policies that match the business value of data with the cost of storage. For example, an organization could decide to migrate all data that has not changed in the last six months from primary storage to Tier 2 storage. As the following example shows, this can result in dramatic immediate and recurring long-term Capital expenditure savings:

25 TB of file data
80 percent of data has not changed in 6 months, therefore 20 TB (20,000 GB) moved to Tier 2
Cost of storage: Tier 1 - $11/GB; Tier 2 - $2/GB
20,000 GB * ($11 - $2) = $180,000 immediate capital expenditure savings
40% growth, therefore 10TB new storage purchased each year
With storage tiering 80 percent (8 TB, or 8000 GB) of new storage can be Tier 2
8000 GB * ($11 - $2) = $72,000 recurring capital expenditure savings

Savings from Optimized Backup

Companies that deploy tiered storage environments can create different backup polices for the primary and secondary storage tiers, which can result in further savings. For example, primary storage can still be backed up normally (for example, daily incrementals and weekly full backups) but Tier 2 can now be backed up much less frequently (weekly, monthly, etc.). Not only does this simplify backup processes and reduce media costs, but it also dramatically improves backup windows.

25 TB NAS environment
Weekly full backup of tier 1, 5 week retention
Cost of backup media: $.75/GB
80 percent of data (20 TB, or 20,000 GB) moved to Tier 2
25 TB x 5 = 125 TB old required backup media capacity
5 TB x 5 = 25 TB new required backup media capacity
(125 TB – 25 TB) x $.75 = $75,000 savings in backup media

Maximizing the Value of Existing Storage Assets

File virtualization also addresses the low utilization problem by allowing IT managers to virtualize or “pool” their existing file storage resources for dramatically improved storage capacity utilization. This means that, instead of having to buy more storage, organizations can make better use of what they already have and boost the return on investment from their existing storage capacity.

25 TB of file data
40 percent current utilization rate, 40 percent increase in utilization rates
Storage costs: $11/GB
25 TB / 40% = 62.5 TB old allocated capacity
25 TB / 80% = 31.3 TB new allocated capacity
(62.5 TB - 31.3 TB) x $11 = $343,200 immediate savings from reduced capital expenditure on new storage purchases

Savings from Simplified Storage Administration

By eliminating the static mappings between client and storage resources, file virtualization dramatically simplifies storage administration for enterprise IT environments. Capacity management, storage provisioning and data migration tasks can now be done online without user disruption. In addition, many tasks that used to be manual, like data migration, can now be completely automated. This typically has a dramatic effect on operating expenses and business operating efficiency, freeing up precious resources to pursue other needed tasks.

$80,000 average FTE Storage Administrator salary
20 percent reduction in management workload
4 full-time administrators on staff
$80,000 x 20 percent = $16,000 increase in efficiency per admin
$16,000 x 4 = $64,000 increase in business efficiency

Note 1: IDC White Paper sponsored by Acopia, “The Economic Impact of File Virtualization: Reducing Storage Costs and Improving Management Efficiency,” Doc # 206435, May 2007

Nigel Burmeister is director of product marketing for F5 Networks. You can reach the author at

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