FICON goes native
Rick Cook
FICON, IBM's new channel architecture for S/390, is finally going native on storage devices. IBM has announced the availability of direct FICON connections on its ESS storage processor and EMC and Hitachi are following suit on their storage processors. Since each FICON is about six times as fast as IBM's older ESCON architecture, and since a native FICON installation can support up to 32 I/O operations per channel at a time, this represents a major performance boost for mainframe storage.
FICON uses the Fibre Channel physical layer and protocol architecture and it's close enough to conventional Fibre Channel that IBM and most other vendors offer Fibre Channel connectivity to SANs as well as FICON connectivity on the same equipment. Previously FICON for storage had been available only using a FICON bridge to connect to an ESCON control unit. This limited performance of the channel to between 1600 and 3000 average I/Os per second, (assuming a 4K channel block size). With native FICON performance rises to between 1800 and 3600 average I/Os per second.
IBM discusses how to implement FICON for storage in its Redbook "FICON Native Implementation And Reference Guide" which is available on IBM's storage website, www.storage.ibm.com.
Rick Cook has been writing about mass storage since the days when the term meant an 80K floppy disk. The computers he learned on used ferrite cores and magnetic drums. For the last twenty years he has been a freelance writer specializing in storage and other computer issues.
