On Sunday, 10/19/2014 at 08:02 EDT, Dennis Foreman <[email protected]> wrote: > The problem only seems to appear if we close the 3270 window, instead of > using #cp disc. If memory serves me (which is always doubtful), we have been > using the "close the window" method for several years, under the assumption > that (since the days of modems), CP allows a machine to keep running (as > long as it has SET RUN ON) when it's console connection is broken, even if > it's running a 2nd level OS. > > Do I mis-remember the design?
Indeed you do. :-) When you close a TN3270 connection, it is converted to an LDSF (DIAG 0x7C) TERMINATE. This creates an unsolicited DE (w/o ATTN) to be given to CP to simulate a power ON condition, causing CP to attempt to write a logo on the device. Since the logical device is no longer there, CP sees a console I/O error (CC=3), forcing the virtual machine into, if memory serves, CP READ. Concurrently, LDSF TERMINATE will disconnect the virtual machine that was connected to the LDEV. The combination of CP READ and being disconnected invokes the "disconnect timeout" from SYSTEM CONFIG. The timer starts ticking. When it expires, the virtual machine is FORCED BY SYSTEM. Alan Altmark Senior Managing z/VM and Linux Consultant Lab Services System z Delivery Practice IBM Systems & Technology Group ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 [email protected] IBM Endicott ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
