On Apr 25, 2011, at 22:20, Glenn Knickerbocker wrote:
>
> You've piqued my curiosity. I've used mode 6 for decades to avoid
> errors in reading and writing simultaneously. Am I just accepting
> quirks you don't, or have I missed some restrictions?
>
I'm thinking of:
Title: z/VM V5R3.0 CMS User's Guide
Document Number: SC24-6079-01
http://publibz.boulder.ibm.com/cgi-bin/bookmgr_OS390/BOOKS/HCSD7B20/2.4.2.6.7
2.4.2.6.7 File Mode Number 6
...
Attention: When modifying an existing file mode number 6 file, it is
possible to damage the file, or even the entire minidisk on which it
resides. This damage occurs when the following conditions are met:
• Some of the updates made to the file or disk by an application
are updated in place.
• CMS terminates (requiring a re-IPL of CMS) before it can write
all of the data to disk.
This now feels more reasonable than I recall it from several years ago.
Perhaps we had a local application that took the risk.
-- gil
