Mercy Medical Center is a 917-bed acute-care facility spread out over three campuses in Des Moines, Iowa. The hospital’s medical imaging department is central to its operations, and clinicians and physicians rely heavily on its Picture Archiving and Communication System (PACS), which digitizes, stores and shares X-ray, CT, ultrasound and MRI studies.
But about two years ago, the medical imaging department realized its storage solution wasn’t up to the task of storing so much data, nor could it handle replicating PACS images from the main data center on the hospital’s main campus to its secondary disaster recovery site about five miles away.
“We had to come up with a solution that was scalable, and that in the event of a catastrophic data center issue, we’d still be able to provide PACS to our clinicians and physicians,” said Roger Wilson, the systems and networking manager at Mercy Medical Center.
It was during that search for a new, scalable SAN solution that Wilson heard about Cisco’s Virtual Storage Area Network (VSAN) technology. A built-in feature of Cisco’s MDS 9000 family of switching modules, VSANs would allow Mercy Medical to segregate PACS replication traffic from production traffic and backup traffic, freeing up availability while helping to prevent data loss in the event of a disaster.
Today, as part of its PACS replication and storage solution, the medical center leverages four Cisco VSANs — one for production, one for backup, one for replication and one for administration.
So now when studies are presented to the PACS application, they are simultaneously written to the medical center’s high-speed disk storage (IBM System Storage DS6800), slower-speed disk storage (IBM System Storage DS4800 and FASt900/DS4500) and tape storage using the Cisco VSAN technology.
The PACS application uses the production VSAN to write data to high-speed storage and slower-speed disk storage. It uses the backup VSAN to write data to tape at the backup data center (which also has a DS6800). Then the replication VSAN is used to mirror data between the two IBM DS6800s.
Because the VSANs segregate the backup data away from the high-speed disk activity, “if anything were to happen to an HBA card for a tape drive, or something like that, I know it won’t impact our primary applications,” said Wilson. “That’s important.”
No SAN Is an Island
Wilson also liked that the Cisco MDS 9509 Multilayer Director gives him “the ability to monitor individual ports for how much data they are moving, what’s the capacity. With that ability to be able to see into the fabric, how it’s being utilized and how close I am to capacity, I can make the necessary changes to add capacity where I need it, before I run into a crisis,” he said.
The beauty of VSANs, explained Deepak Munjal, Cisco’s manager of data center marketing, is that they “give you the same level of separation as if you had multiple SAN islands. But you get the benefit of having a single or fewer devices to manage, fewer devices to control, and the other economies of scale you get with data consolidation.”
That’s because with VSANs “the servers really don’t need to understand that they are in an isolated virtual SAN environment,” said Munjal. “The performance is the same. The functionality is the same.” Except that you no longer need so many SAN islands or boxes. And with Cisco’s Inter-VSAN Routing, or IVR, technology, enterprises can easily link two or more VSANs.
“All of the issues we used to have with VSANs — performance, administration, flexibility, connectivity — have gone away,” stated Munjal. “VSANs and IVR are now part of the fabric, parts of the switch. You no longer need an external device. You no longer need to install an additional blade into your switch. What we’ve done at Cisco is made VSANs and IVR just another feature on the switch … another tool that gives you a very flexible approach to building your SAN.”
For Wilson and Mercy Medical Center, the Cisco technology has provided the scalability and peace of mind they were after. In the case of a catastrophic event, the system can point the backup servers at the backup DS6800, and PACS would be online with no loss of information.