Denmark-based SDC Udvikling A/S is an application service provider that develops and operates IT systems for more than 85 banks, servicing thousands of customers.
Its distributed infrastructure supporting these banks has been causing SDC downtime and headaches for too long.
The 85 banks are spread across 550 locations with a file server at every location, supporting a total of 6,500 workstations. Every time one of these servers would go down, SDC had to get it repaired and restored. "It would take an entire day to get the new hardware out there and restore the data," SDC IT consultant Bo Christiansen said.
To fix this problem, SDC consolidated its infrastructure by replacing 550 old file servers running OS/2 with just 12 Dell servers running Microsoft Windows 2000 and Windows 2003. More importantly, these Dell servers are located at SDC's headquarters, and all the file serving is now done from this central location.
But this raised a new problem of what storage to provide. Previously, each file server had its own internal RAID. As the search for a new storage supplier came up, other departments within SDC's data center latched onto the action.
SDC was operating several different, isolated Fibre Channel (FC) SANs, each with different storage, including Hewlett-Packard Co. (HP), Storage Technology Corp. (StorageTek), Hitachi Data Systems (HDS) and IBM arrays. The applications running on these SANs included accounting, Web servers and home banking.
SDC weighed up its options
"One choice was to pick one FC SAN and collapse the others into it, but it wasn't cheap enough to connect all our hosts to FC," Christiansen said. The firm also looked at an iSCSI offering from StorageTek and FalconStor Software that would have taken all its SANs and exposed them through a single interface, but this was too complex, according to Christiansen.
Next, SDC experimented with connecting its Internet banking application to its HDS arrays, but it took six weeks to get everything right. "Getting the HBA's from Emulex to work together with the Windows drivers was impossible; if the drivers were off one digit, it wouldn't work," Christiansen said. Then they looked at HP's EVA but found it to be too expensive. "After three years, the maintenance would cost the same as a new SAN." EMC's Clariion was ruled out for being too expensive also.
Finally, SDC decided to take a shot at the iSCSI vendors, and all but one was able to connect to enough hosts and provide the throughput the company required. The only survivor was EqualLogic Inc.
The firm worked with EqualLogic distributor Consolidate IT to implement an iSCSI-based SAN consisting of eight EqualLogic PS Series storage arrays that provided 32 terabytes (TB) of storage capacity for 120 Dell servers -- 100 of which are configured with Adaptec Inc. iSCSI 7211C HBAs. These 120 Dell servers include the 12 mentioned earlier that were used to consolidate the remote file servers.
SDC's plan is to phase out its FC SANs and move as much as possible to the iSCSI SAN. So far, it has migrated off 3 HP MSA 1000s and is currently moving off a HDS 9700. The migration off the branches is performed with a tool from Microsoft called Robocopy.
One of the key requirements of the SAN was an iSCSI boot capability enabled by the Adaptec HBAs and EqualLogic's software. This feature allows SAN servers to be remotely configured with the desired operating system and application image speeding up recovery when a server needs to be redeployed or replaced.
The savings are a matter of adding the difference between FC and iSCSI components.
"For each $3 spent on FC, we spend $1 on the IP SAN -- so a ratio of 1 to 3," Christiansen said. For maintenance and support, he said he would need more than double the amount of time. "The FC SANs we have can only be operated by specially trained personnel whereas the IP SAN can be operated by our networking staff."
Christiansen does have some requests from EqualLogic as the startup continues to develop its product. Support for synchronous mirroring, shared image and a SAN admin software development kit in C, C++ or C# languages would be useful, he said.
In the meantime, SDC is adding more EqualLogic boxes to provide nearly 70 TB of IP storage for more than 200 servers.
According to technology watchers on both sides of the Atlantic, the SDC Udvikling A/S infrastructure is the largest iSCSI SAN in Europe, and one of the largest in the world.Click here for more of today's news.