The Andrew File System on OS/2 and SNA

Porting a distributed application from one environment to another can be significant, particularly when performance is an important consideration. The Andrew File System (AFS) is a distributed file system designed to be heterogeneous and scalable, and it runs efficiently on variations of Unix. A port of AFS to Operating system/2 (OS/2) encountered an assortment of problems at various levels. The port, performed as a sequence of two ports, first investigated feasibility and performance issues and then integrated AFS into the OS/2 environment. Additionally, the migration from the original AFS network protocol, user datagram protocol internet protocol (UDP/IP), to systems network architecture (SNA) posed challenges, not the least of which was the change from a connectionless to a connection-oriented protocol. OS/2 and SNA demonstrated their viability as platforms for distributed applications by providing competent support for this performance-critical software, but substantial modifications to the AFS structure were necessary to achieve an efficient OS/2 implementation that preserved the AFS file system interface and semantics.<>