* Just how much can you save with SAN, NAS and mgmt. software?
In last week’s newsletter, we discussed the use of virtualization as a way to save on storage costs. This week, we’ll cover the nuts and bolts of how to realize these savings.
Storage virtualization – whether through storage-area networks (SAN), network-attached storage (NAS) or a combination of the two – cuts costs in two main ways. First, it increases overall utilization of the storage infrastructure – meaning that IT executives need to purchase fewer disk arrays and storage subsystems to meet their needs. Second, it reduces the total cost of ownership (TCO) of each gigabyte of storage (particularly when it’s used in conjunction with storage management software).
Specifically, SAN/NAS technology increases utilization from the average of about 30% typical for most direct-attached storage (DAS) scenarios to either roughly 60% (when used alone) or 85% (when used in conjunction with storage management software). Additionally, DAS technologies carry a cost of ownership of roughly $100 per gigabyte, while SAN/NAS technologies reduce that cost to $50 per gigabyte, including depreciated hardware, software licenses and maintenance personnel. (NOTE: Last week these figures were incorrectly listed as $10 and $5, respectively. Sorry for the confusion.)
The upshot? Increased utilization and lower TCO combine to deliver cost savings of 300% or more for enterprises large enough to justify the use of SAN and NAS technologies. Typically, it begins to make sense for a company to deploy SAN/NAS when it has somewhere between 5 terabytes and 10 terabytes of storage.
Here’s how the numbers play out for a typical company in that range:
Assume a company has 6T bytes of data to store. With DAS, the TCO is roughly $100 per gigabyte and utilization is typically 40%. Six terabytes of data would therefore require approximately 15T bytes of available storage, thus costing an organization approximately $1.5 million per year to maintain. Moving that storage to a SAN/NAS environment increases the utilization – thereby reducing the amount of storage required from 15T bytes to 10T bytes. It also decreases the per-gigabyte cost of that storage from $100 to $50, cutting costs to $500,000 per year. Adding storage management software improves utilization still further, enabling those 6T bytes of data to be stored in roughly 7.1T bytes of available storage, and reducing the yearly cost to $353,000 – a total savings of approximately 325%.
It’s not generally recommended for a company to make a forklift upgrade from DAS to SAN/NAS with storage management software. Most do it in stages: first deploying SAN, NAS, or a combination thereof, and then migrating to a fully managed environment. Depending on the size of the organization, the migration can take from six to 36 months.
Also, it’s worth noting that few companies sign off on either SAN or NAS exclusively. Generally, NAS is more effective for file-format data, while SAN performs better for record-format data (such as databases).
The bottom line: If you’ve got more than 5T bytes of data, you should definitely be considering virtualized storage. It could save you a bundle.
