RCOPROB@HDETUD1.TUDELFT.NL (Rob van Hoboken) (02/06/90)
I've got two rather difficult question, which of course I couldn't find in the proper docs. Both involve both /370 as well as XA systems. Replies from both sides would be appreciated. 1. incore directory I would like to obtain data about all users defined in the directory, without having to read the source or object directory from DASD. Data I am after are mostly MDISK definitions (vaddr, start, size, volume). Is there any way to get to the incore version of UDIRECT blocks (get CP to page in these blocks for me, and return a pointer to me) ? 2. doing I/O to ALL DASD How would CP react if I take one of my VDEVBLOKs, and change the RDEVBLOK pointer and extent descriptors, i.e. make an MDISK vaddr of my machine a full pack minidisk on just any real device ? Of course I 'only' want to read :-) I guess CP wouldn't mind if I overlay a not owned disk with a full pack, and even a system owned shouldn't give a hoot. How about disks that are already ATTACHed to some (MVS) guest ? How would CP (and MVS) feel about my doing some I/O on their DEEDICATEd disks ? I would like to issue SENSE comamnds to ALL disks in the farm and READ the ALLOCATION MAP from all OWNED disks. How about it, has any of tried this before ? How did it work out, or why could it not work ?
DMARTIN@UAFSYSB.UARK.EDU ("Daniel P. Martin") (02/06/90)
>2. doing I/O to ALL DASD
Zapping control blocks is probably an unnecessarily dangerous approach
(not that it isn't fun to do from time to time... :-) ). If you're on
a reasonably current VM R5 system, or on VM 6 at any working level, take
a look at diagnose code x'E4', which allows you to perform various
minidisk extent management operations including definition of full-volume
minidisk overlays for anything that's ATTACHed to system. As I don't
have access to an XA system or documentation, I can't say if this is
supported under XA as well as /370 VM.
Nuking the VDEVBLOK will work too, but with the DIAG interface available,
it's an "overkill" solution -- sort of like swatting flies with Buicks.
Regards,
-dan.
Daniel P. Martin -- Systems Programmer III
University of Arkansas Main Campus - Fayetteville