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=============================================================================== Robb Kambic Unidata Program Center Software Engineer III Univ. Corp for Atmospheric Research address@hidden WWW: http://www.unidata.ucar.edu/ =============================================================================== ---------- Forwarded message ---------- Date: Fri, 27 Apr 2001 22:31:29 -0600 From: Tom Yoksas <address@hidden> To: Gilbert Sebenste <address@hidden> Subject: 20010427: McIDAS ADDE functionality under RedHat 7.1 Linux >From: Gilbert Sebenste <address@hidden> >Organization: NIU >Keywords: 200104280154.f3S1sSL24870 McIDAS ADDE RedHat 7.1 Linux inetd xinetd Gilbert, et. al., I am not writing to jump into the Solaris vs Linux debate (although I think that Solaris x86 runs much better than Linux, but I run Linux at home :-), I am writing to make a small comment on McIDAS ADDE functionality under RedHat 7.1 Linux. Gilbert noted: ... >BTW, McIDAS under 7.1 works >fine, except my ADDE server suddenly stopped working from those people >trying to get data from me. I think it's back up again...will check. The problem that Gilbert ran into was caused by the upgrade from RedHat 6.2 Linux to 7.1. The story is as follows: o RedHat 6.x Linux runs inetd, and inetd is configured with /etc/inetd.conf o RedHat 7.x Linux no longer runs inetd. Instead, it runs xinetd, and xinetd uses a different approach to configuration: files in the /etc/xinetd.d directory o RedHat 7.x Linux includes an executable called inetdconvert (a Python script) that converts /etc/inetd.conf entries to files in /etc/xinetd.d o newer versions of Linux (and FreeBSD) include what looks like all registered uses of port numbers in /etc/services. Port 500 (both TCP and UDP) is registered to a program called 'isakmp'. o McIDAS ADDE uses ports 500 and 503 for communications: port 500 for uncompressed transfers and port 503 for compressed transfers All of this sounds reasonably OK until one realizes that there is a port conflict between McIDAS ADDE uncompressed data transfers and 'isakmp'. This is easily gotten around by commenting out the 'isakmp' entries in /etc/services and sending a USR1 signal (not a HUP) to xinetd. The problem, however, is that inetdconvert does NOT convert the /etc/inetd.conf entries for ADDE services (mcserv and mccompress) correctly. The /etc/services entries for mcserv (port 500) and mccompress (port 503) get deleted in the upgrade from RedHat 6.x to 7.x, AND the configuration files created in /etc/xinetd.d for those services do NOT include the port configuration information that would obviate the need for an entry in /etc/services. The solution that returns ADDE functionality is the addition of a port definition line to the /etc/xinetd.d/mcserv and /etc/xinetd.d/mccompress files followed by the sending of a USR1 signal to xinetd (which tells it to reread its configuration files). After these steps were performed on Gilbert's machine, ADDE returned to functionality. I will be updating the Linux section of the Unidata McIDAS 'Notes and Warnings" web page: http://www.unidata.ucar.edu/packages/mcidas/770/mcx/warnings_mcx.html with the steps needed to recover from the RH 6.x to 7.x upgrade later this weekend. Tom -- +-----------------------------------------------------------------------------+ * Tom Yoksas UCAR Unidata Program * * (303) 497-8642 (last resort) P.O. Box 3000 * * address@hidden Boulder, CO 80307 * * Unidata WWW Service http://www.unidata.ucar.edu/* +-----------------------------------------------------------------------------+