The Skinny on Storage
A few years ago the local government of Gaston County, N.C., suffered the rare loss of two hard disks attached to the same server. IT managers, who accepted that the cost of doing business meant several thousand dollars in new hardware expenses, nonetheless recoiled when they learned that 90 days of digitized billing records for the county's ambulance service had been lost.
The bad news: The data had been stored on one of the two failed drives and backed up on the other.
"We had to rekey all the data," recalls Brandon Jackson, who as CIO of Gaston County had a workplace epiphany: His agency needed a new data storage approach.
The county purchased a Compellent storage area network with thin provisioning technology that treats all attached storage devices as a virtual pool and ensures that storage devices are used almost to capacity before IT managers must add new storage. Now the county's data is automatically backed up without direct monitoring by technicians.
More efficient storage is crucial, says Jackson, as the amount of data the county must store expands rapidly. The local government is transferring paper records to digital form and adopting new graphics-heavy tools, such as a geographic information system that uses digital maps overlaid with critical data -- everything from the location of water, gas and sewer lines to real estate parcel information.
"Managing all those applications on individual servers and hard drives wasn't working," Jackson says.
As the data storage needs of state and local agencies continue to grow, experts say more of them are turning to thin provisioning.
With traditional technology, discrete blocks of storage are set aside for every application or user who might need it. The tendency of users to overestimate storage needs frequently results in an over-allocation of storage capacity. The result is that utilization rates can be as low as 20 percent.
Mark Peters, a senior analyst at the Enterprise Strategy Group, says the inefficiency is like a bus that won't let on new riders despite being only 20 percent full because passengers are saving seats for friends and family members, including the unborn, who might want to ride in the future.
The percentage of IT departments surveyed that now use thin provisioning
Source: TheInfoPro survey of 1,000 large organizations
"The old way of provisioning led to appalling levels of utilization," Peters says. "If other resources in the world were used as poorly as storage space once was, people would be laughed at."
Inefficiency was tolerable when IT constituted a small part of organizations' operations and budgets, and the cost of storage generally declined at a rate that offset increased use. Recently, however, the cost of storage hasn't fallen fast enough to compensate for surging IT use and the corresponding increase in demand for storage.
"Over the last few years there has been a massive focus on doing things not just effectively, but more efficiently in terms of using fewer resources," Peters says. "The big mantra in IT is to do more with less."
Thin provisioning delivers physical storage on demand. If a particular application experiences a rapid spike in storage needs, the system automatically dips into the shared storage pool to provide it. This lets IT managers allocate considerably more storage than the physical capacity they actually possess. Technicians can easily monitor the system, or any part of it, from a single computer screen. As the networked storage devices approach full capacity, the system alerts technicians to buy more.
Brevard County, Fla., also adopted a SAN with thin provisioning from Compellent, saving on electricity and floor space.
With its older storage technology, the county might have had to buy 3 terabytes of storage this year, says Michael Bowen, information systems director of the county's Clerk of the Court office. Now, with thin provisioning, he may only need to buy 1 terabyte.
Bowen says that six years ago, the main data center was knocked out by a hurricane, and county records were inaccessible for several days while data was transferred from the backup storage center. The new SAN with thin provisioning offers much faster data replication, says Bowen. "If we lose our main facility, we can come online with the second facility."
Here are the leading reasons IT departments embrace thin provisioning: