Health record storage needs are taxing the ingenuity of health care IT professionals faced with their institutions' ballooning quantities of data. Storage makes for a challenging conundrum. Data sets including huge image files must be available rapidly for a time, then stored securely for years, all according to Health Insurance Portability and Accountability Act, or
John Fagg, manager of storage services at University of Utah Health Care in Salt Lake City, said data at his institution is "not quite doubling every year, but [it's] close."
For many hospitals, storage area network (SAN) technology, in various forms, is the best way to marry fast performance with expandability. Utah Health Care, for example, is relying on Fibre Channel SANs and Brocade SAN switches to handle its burgeoning data.
SAN technology is virtual storage, which means that the logical units of storage are separated from the disk drive arrays that physically store the data. Logical units are allocated to different applications but can be expanded quickly across storage arrays, should the need arise.
"You can grow a [logical unit] on the fly and spread it across multiple RAID groups," explained Jeffrey Haddon, storage administrator at Utah Health Care. Using the technique of thin provisioning, it's possible to assign an application a 1 terabyte (TB) logical unit that utilizes only 200 GB of disk. "It's easy to grow it in the background," as needed, without affecting end-user performance, he added.
Despite the appeal of SAN technology, some medical software vendors either do not support it or are reluctant to do so, according to Steve Huffman, vice president and CIO of Memorial Health System in South Bend, Ind.
"Some applications are still not on our SAN. Some vendors say they're not comfortable with the SAN environment," Huffman said. Nonetheless, he has implemented SAN-based health record storage wherever possible. "We have moved a significant portion of our applications -- Cerner, PeopleSoft [now Oracle Corp.] and McKesson -- to our SAN."
Fibre Channel SANs: Resilience reduces downtime
Fibre Channel SAN technology, which is ideal for connecting servers to shared storage devices, has proved its worth at Metro Health Group in Wyoming, Mich. "We have been a Fibre Channel site for years," said Aivars Apsite, technology manager at Metro Health. "It's very resilient. It doesn't really go down. It's highly redundant and failovers are seamless."
The institution has redundant Fibre Channel SANs in its primary data center and its secondary data center 12 miles away. The centers are connected by redundant fiber links, and data is mirrored from one to the other.
The redundant setup was tested recently when an automobile accident severed one of the fiber links. A Fibre Channel switch failed on another occasion. "In both instances, our Fibre Channel redundancy worked flawlessly, and we never incurred any downtime," Apsite said.
The hospital recently completed a major storage upgrade that more than doubled its storage capacity -- from 120 TB to 254 TB -- using the Hewlett-Packard Co. StorageWorks XP20000 series disk array along with the HP StorageWorks Enterprise Virtual Array 8400.
Enterprise flash drives: "Near real-time retrieval"
Although Fibre Channel SAN performance suffices at many institutions, Wausau, Wis.-based Aspirus, a network of hospitals serving northern Wisconsin, has turned to flash memory to provide extremely fast response time in its health record storage system.
In Aspirus' data center, EMC Corp. enterprise flash drives are housed in a Clariion CX4 Model 960, which is known as "tier 0" in Aspirus' tiered storage architecture. That architecture is fleshed out with iSCSI SANs at tier 1, Serial Advanced Technology Attachment, or SATA, drives at tier 2 and EMC Centera archival storage at tier 3, which handles long-term storage for its picture archiving and communication system (PACS) from Sectra AB, cardiology images and video.
Aspirus' Epic Systems Corp. software applications also are served by the EMC enterprise flash drives. Later this year, Aspirus will add an Oracle decision-support application that will also store active data on the flash storage. "It gives physicians near real-time retrieval," said Tom Whalen, server systems team leader at Aspirus. "We can serve more patients through the system. It both increases volume and quality of clinical care."
Business applications, payroll, ERP and high-speed reporting applications also are on the tier 0 flash drives. In all, Aspirus is storing about 4.5 TB of data on flash memory, and may move its Sectra AB PACS data to flash in the future, according to Whalen.
ISCSI SANs offer flexible health record storage
Like Aspirus, Community Health Partnership Inc. in Eau Claire, Wis., has implemented iSCSI SAN storage technology. Community Health is relying on Dell Inc. EqualLogic iSCSI SANs for the bulk of its storage needs, from active data to email archiving. The speed, flexibility and low cost of iSCSI gives the health care provider a one-size-fits-all approach to health record storage.
We have been a Fibre Channel site for years. It's very resilient. It doesn't really go down. It's highly redundant and failovers are seamless.
Aivars Apsite, technology manager, Metro Health Group
"We can take any SAN and upgrade the firmware easily. The PC 600 to the PS 6000 -- all the firmware is the same," said Andrew Violet, systems engineer at Community Health.
Community Health's storage architecture consists of nine iSCSI SANs in three groups of three, handling a total of 90 TB of data. One group of high-performance SANs handles active data, working in tandem with another local SAN. The third SAN group handles backup at a remote site.
When it embarked on implementing Allscripts-Misys Healthcare Solutions Inc.'s electronic medical record (EMR) software, Community Health considered adopting a Fibre Channel SAN, but the organization found the higher speed did not justify the steep additional cost. "Throughput is important -- but it's not nearly as important as the actual amount of data we can store," said Keith Grey, IT technical services manager and security officer.
Staying with iSCSI allowed Community Health to implement Allscripts' EMR software by spending only $65,000 for storage upgrades instead of the $335,000 that Fibre Channel would have required, Grey said.
Deduplication technology avoids multiple instances of the same data
Left unchecked, the sheer quantity of data in long-term archives could break the health record storage budgets of some organizations. To fight back, many hospitals use data deduplication technology to avoid storing the same information many times -- in some cases, tens or hundreds of identical instances.
Utah Health Care is implementing both NetApp Inc. and EMC Data Domain deduplication technology to justify storing the data on disk for longer periods, thereby assuring it will be accessible faster than if it were archived on tape. Deduplicated data is encrypted and transmitted to an off-site storage facility. Once there, it is "un-deduplicated" or "rehydrated," so the full record of all data instances can be stored for archival purposes on tape, Haddon said.
Similarly, Community Health is using VMware Inc.'s vSphere to perform deduplication of the data within its health record storage system, Grey said.
Stan Gibson is a contributing writer based in Boston. Let us know what you think about the story; email firstname.lastname@example.org.
This was first published in April 2010