The sysplex is a big issue at our shop, so this will be interesting, more so than the Y2K eleven years ago ;-). Thanks for responding.
James Chaplin Systems Programmer, MVS, zVM & zLinux Base Technologies, a CA Technologies Company -----Original Message----- From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On Behalf Of McKown, John Sent: Tuesday, November 29, 2011 2:05 PM To: LINUX-390@VM.MARIST.EDU Subject: Re: Question of UTC vs Local Time If you're application is requesing local time and you set up the TIMEZONE information correctly, then I doubt you'd see any problem. The problems occur if the application requests GMT time or does the assembler STCK or STCKE instruction to get the TOD clock from the hardware directly. You mentioned z/OS, which I'm better at than z/Linux. The only problem that I can foresee is if you change the TOD clock to "move backwards" and your running in a z/OS sysplex. You __cannot__ back up the TOD clock in a sysplex. Period. End of discussion. There are two things which you can do. One is to simply wait for "n" hours for the GMT version of the TOD clock to move forward from the local TOD clock time (US EST would be a >5 hour wait). This is not likely to go over well with management. <grin>. The reasonable thing to do is to create an entirely new, and unused, version of all your couple datasets and use the new versions on the IPL after the TOD is set to GMT. Oh, and watch out for database software such as DB2. It uses TOD timestamps instead of local time. But I don't know enough about DB2 to know what happens if the TOD "backs up". I will allow the gurus of Linux to talk about the impact in Linux. I'm too ignorant. -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * john.mck...@healthmarkets.com * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > -----Original Message----- > From: Linux on 390 Port [mailto:LINUX-390@VM.MARIST.EDU] On > Behalf Of CHAPLIN, JAMES (CTR) > Sent: Tuesday, November 29, 2011 11:38 AM > To: LINUX-390@VM.MARIST.EDU > Subject: Question of UTC vs Local Time > > Has anyone moved from Local time (EST) to UTC with zLinux?? > Any comments > or experiences to share? > > > > One of our upper level managers want us to look at what it > will take to > move everything that is on Local time (Linux & zOS) to UTC. From a > systems point of view I cannot think of an impact, just on in house > applications., that have self written timestamps. > > > > James Chaplin > > Systems Programmer, MVS, zVM & zLinux > > > ---------------------------------------------------------------------- > For LINUX-390 subscribe / signoff / archive access instructions, > send email to lists...@vm.marist.edu 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/ > > ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu 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/ ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to lists...@vm.marist.edu 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/
