On Fri, 21 Apr 2006 15:41:20 -0700, Skip Robinson
<[EMAIL PROTECTED]> wrote:
>To shut down, we VARY XCF OFF. The HMC beeps and turns red. We move on. No
>system reset.
>
>
>Bruce Black <[EMAIL PROTECTED]>
>Subject
>Re: Fw: IXC102A automated by SFM ?
>
>
>What do you do to shutdown? The red icons indicate that the LPAR is not
>running, meaning that it is in STOP state or some sort of error state,
>so you must have done something.
>
>System reset is generally a good thing on a shutdown system. Among
>other things, it does a "selective reset" to every I/O device, which
>releases any RESERVES or pending conditions, resets path group
>definitions, and generally clears the device.
>
>--
>Bruce A. Black
Skip,
If you do not system reset before replying 'DOWN', it is possible
that the outgoing system may still have I/O in flight while the other
systems' peer applications are recovering for the demise of their
partner. This can lead to data integrity issues. As Bruce points out,
the system reset has the effect of purging outstanding I/O, which prevents
this situation. If the target system's I/O is known to have completed,
the other systems can safely take over whatever resources its applications
were using without fear of unserialized collision. In most cases, by the
time you see the outgoing system stopped, its I/O is also complete. But
that isn't guaranteed unless you system reset. So, yes, you have been
lucky to avoid problems.
Bill Neiman
z/OS Development
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