To set a fairly precise time difference, trap the results of a QUERY TIME in an EXEC, calculate the displacement to the time you want, then do your SET VTOD from the EXEC. We did something like this for y2k testing.
Peter -----Original Message----- From: The IBM z/VM Operating System [mailto:[email protected]] On Behalf Of Florian Bilek Sent: January 30, 2009 03:08 To: [email protected] Subject: Using VTOD Dear all, Due to historical reasons we run our host systems on local time (CET/CETS = EAST +1h/+2h). Well, all the years this served well but due to some services that require UTC we have to change now to UTC. In a first stage we would like to run only those services necessary with UTC. In order to carefully test our applications we are using z/VM and the VTOD feature were we can simulate the test systems (z/OS and z/LINUX) the switch of the hardware clock to UTC. This works but for the operating staff it is quite a nightmare. What I mean is that we have to define a Reference time that is exactly 1 hour from the system time. There we face following issues: 1.) The SET VTOD command does not accept parameters such as current time -1h. This is quite problematic since we will always have a small difference from the hardware clock depending how exactly the operator entering the time and hits enter. 2.) To use this time for the MSGPROCs and GUESTmachines we defined a User called GMTETR that is nothing doing except setting the time and run as time source. Unfortunately, since the SET VTOD makes a system reset, this user drops after the command to CP READ and after some time it seems to be logged off from the system. This is quite annoying. We tried CONCEAL option in order to REIPL the GMTETR machine but nothing is happening. I would like to ask two questions: How can we set a time difference of exactly one/two hours from the hardware clock? What can be done that the GMTETR is not forced from the system? Thank you in advance, Kind regards, Florian The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review retransmission dissemination or other use of or taking any action in reliance upon this information by persons or entities other than the intended recipient or delegate is strictly prohibited. If you received this in error please contact the sender and delete the material from any computer. The integrity and security of this message cannot be guaranteed on the Internet. The sender accepts no liability for the content of this e-mail or for the consequences of any actions taken on the basis of information provided. The recipient should check this e-mail and any attachments for the presence of viruses. The sender accepts no liability for any damage caused by any virus transmitted by this e-mail. This disclaimer is property of the TTC and must not be altered or circumvented in any manner.
