On 11/11/2013 11:43 AM, DASDBILL2 wrote: > Besides getting access to another system within the same SYSPLEX, you can > also indirectly and inadvertently cause a major outage on a production system > in the same SYSPLEX if certain resources are shared. E.g., I once was given > access to an "isolated", "stand-alone", "sandbox" test system on which I > tested some authorized system type software. I ran my test and crashed the > test system. The production system hung up because it couldn't get its > production JES2 Checkpoint data set because the production and sandbox system > had some shared DASD and my test on the sandbox had crashed it while the JES2 > running on the sandbox system had done its normal, periodical reserve of its > checkpoint data set which happened to be on the same shared device as the > checkpoint data set for the production system. With clever and expert > operators and management standing by during my test, this problem was quickly > resolved and the production system was happy again within one minute, but > this taught me t h e lesson that there is probably no such thing as a standalone, independent, crashable, sandbox test system. Expect the unexpected. > > Bill Fairchild > Franklin, TN > > ----- Original Message ----- > > From: "Jon Perryman" <[email protected]> > To: [email protected] > Sent: Monday, November 11, 2013 11:27:01 AM > Subject: Re: APF in JCL step > > once within the SYSPLEX, you can often get access to the other systems (more > complicated but often doable). > If your test system requires concurrent access to volumes that are on-line to production systems in order to function, it is not a true standalone system. A standalone system by definition only requires its own dedicated DASD.
It makes sense for a standalone/test system to be able to access production volumes in order to repair an inoperable production system in an emergency, but the LPAR definition for the test system should by default only have "test" volumes owned by that system on-line. Putting a production volume on-line to a test standalone system should require a deliberate act and not be done casually if the production system could potentially access the volume. Similarly, the standalone system volumes should by default be off-line to the production system whenever the standalone system is active. True system isolation can be achieved (this was done all the time during Y2K testing), but you do have to follow all the rules. -- Joel C. Ewing, Bentonville, AR [email protected] ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
