Midrange Stuff, OS/400 Edition--EMC Chooses Crossroads to Connect Symmetrix DMX Disk Array to iSeries

EMC, the only provider of external iSeries disk besides IBM, and Crossroads Systems, a developer of storage protocol conversion products, have expanded their technology partnership to benefit EMC's OS/400 customers. The new offering from EMC uses Crossroads technology to allow iSeries servers to connect directly to EMC's next-generation Symmetrix DMX arrays, via Fibre Channel, thus giving customers more advanced data replication and disaster recovery options than before.

Under the companies' expanded OEM agreement, EMC's OS/400 customers will have the option of buying Crossroads' technology to connect their OS/400 servers to Symmetrix storage arrays using Fibre Channel, the de facto standard storage protocol for storage area networks (SANs). Crossroads entered the OS/400 market about a year ago, when it introduced OS/400 support in its line of ServerAttach SCSI-to-Fibre Channel storage routers.

Crossroads had to do some bit-twiddling to support OS/400's storage "quirks" within its products, but it eventually succeeded and rolled out two ServerAttach devices that let older SCSI-based AS/400s communicate via tapes and disks that are part of Fibre Channel-based SANs (see "CrossRoads Aims to Bring SANs Within Reach of AS/400 Masses").

EMC is OEM-ing a derivative of the ServerAttach technology and selling it to OS/400 shops as its own product. The device is similar to another EMC product, called an 8HDA, which is composed of a standard IBM disk carrier and EMC-developed firmware, which plugs directly into the OS/400 server's disk drive and allows an 8XX AS/400 or iSeries server to boot directly, via SCSI, off EMC's disk arrays. The new devices, called FHDAs, are similar to the 8HDAs, except that the firmware uses Crossroads technology to support Fibre Channel connectivity instead of SCSI.

Without the FHDAs, EMC could not offer the same level of OS/400 connectivity with its new high performance Symmetrix DMX disk arrays as it could with its older Symmetrix arrays. The new Symmetrix DMX arrays only support Fibre Channel, and while Fibre Channel-equipped iSeries servers could still store data on the Symmetrix DMX array, without a native Fibre Channel load source, the lack of a direct connection meant that EMC would not be able to provide advanced high availability and disaster recovery features, through such offerings as TimeFinder and Symmetrix Remote Data Facility, in an iSeries-Symmetrix DMX environment.

"This is just for the load source storage side," says Rick Aguiar, the chief technologist for the iSeries at EMC. "We've been able to attach with Fibre Channel since it was announced. We were there. What I didn't have was the capability to support the load source drive. For some it was okay; for others it was not okay. We had to keep a SCSI connection."

EMC announced its next-generation Symmetrix DMX disk arrays in early 2003. The new Symmetrix arrays are based EMC's Direct Matrix architecture, which features a dizzying assortment of dedicated paths (up to 128 on high-end arrays) between the individual disks and the server's memory cache. EMC claims its Direct Matrix architecture represents a quantum leap over the bus- and switch-based architectures that are used in EMC's older Symmetrix arrays, as well as the offerings from its primary competitors in the high-end disk array arena, IBM and Hitachi Data Systems. The Symmetrix DMX array's maximum total system bandwidth is a 64 GB/sec, which, EMC says, is six times better than its nearest switch-based competitor. With standard hardware and software, EMC says, its Symmetrix DMX is still twice as fast as its nearest competitor.

EMC started shipping Symmetrix DMX in the first half of the year, but didn't provide OS/400 or FICON mainframe connectivity until September. For more information on Symmetrix DMX and iSeries, see "EMC to Support iSeries with New Symmetrix DMX Disk Arrays."

The new Crossroads-powered FHDAs are now available from EMC. For more information, go to www.crossroads.com and www.emc.com.

This article has been corrected since it was first published. The article originally stated that EMC was the only provider of external disk for the iSeries. In fact, EMC is the only provider of external iSeries disk besides IBM. Guild Companies regrets the error. [Correction made 12/1/03.]