The resolver address space is used by applications for host name-to-host address or host address-to-host name resolution. If your applications require that support, then you must configure your system with a physical file system that supports an AF_INET or AF_INET6 domain. You can do this by adding either a FILESYSTYPE or a SUBFILESYSTYPE statement to your BPXPRMxx member. If you do not require that support, you can remove the RESOLVER_PROC specification from your BPXPRMxx parmlib member.