All,
No. I am not talking about scanning the volume nor reading the VTOC. I
am not touching, in any way, the actual disk data. I am getting
low-level info from the sub-system using CCW Commands:
x'27' PSSF - Perform Sub-System Function, functions 18/47, 18/0B
x'64' RDC - Read Device Characteristics
x'54' SSS - Sense Subsystem Status
Yep, not your common CCWs.
Tony Thigpen
Seymour J Metz wrote on 6/14/24 2:51 PM:
The OP was asking about scanning the entire volume, not just the VTOC.
--
Shmuel (Seymour J.) Metz
http://mason.gmu.edu/~smetz3
עַם יִשְׂרָאֵל חַי
נֵ֣צַח יִשְׂרָאֵ֔ל לֹ֥א יְשַׁקֵּ֖ר
________________________________________
From: IBM Mainframe Discussion List <[email protected]> on behalf of Mike Shaw
<[email protected]>
Sent: Friday, June 14, 2024 1:35 PM
To: [email protected]
Subject: Re: Getting dasd info
No. With the right combination of DYNALLOC, OPEN and RDJFCB you can open
the VTOC and execute a channel program that reads the entire VTOC without
any kind of SAF authorization. It can also be read with BSAM but that is a
little slower.
Mike Shaw
MVS/QuickRef Support Group
Chicago-Soft, Ltd
On Fri, Jun 14, 2024, 1:17 PM Farley, Peter <
[email protected]> wrote:
Doesn’t physical scan of VTOC/VVDS areas on DASD (or for that matter
directly issuing CCW’s to any DASD for any reason) also require at least
SAF authorization (if not also APF authorization) to allow access under
z/OS?
Peter
From: IBM Mainframe Discussion List <[email protected]> On Behalf
Of Matthew Stitt
Sent: Friday, June 14, 2024 1:00 PM
To: [email protected]
Subject: Re: Getting dasd info
Take a look at file 527 on the CBT tape. Program(s) DADSM and LISTICAT.
Both programs do a scan of the disk volumes and generate reports on VTOC,
VVDS, etc.
Matthew
On Fri, 14 Jun 2024 12:08:54 -0400, Mike Shaw <[email protected]>
wrote:
Tony,
You can run in problem program state and key and issue a UCBSCAN macro to
get a list of UCBs and UCB copies for that z/OS system. You can then run
that returned list and choose only the online DASD UCBs. For each of those
that you are interested in, issue an LSPACE SVC specifying the UCB
address.
That will get you a good picture of free space info for that volume, and
it's quick.
To go deeper and get a list of all data sets on the volume and/or a volume
map, you have to read the VTOC and process it. You can do that without
being APF authorized also, if the volume is allocated to your job step.
The CVAFTST macro will tell you whether or not a particular DASD volume
has
an indexed VTOC or not.
Mike Shaw
MVS/QuickRef Support Group
Chicago-Soft, Ltd.
On Fri, Jun 14, 2024 at 11:20 AM Tony Thigpen <[email protected]> wrote:
All,
I have a z/VSE program that I want to start using with z/OS. The program
issues several CCWs to the DS8000, such as SNS, SSS, RCD, & PSSF that
are either volume specific or subsystem specific. Not file specific.
My first question is in the area of getting access to a specific volume
on z/OS.
In z/VSE, I just do an ASSGN to the disk and issues the EXCPs.
On z/OS, I expect I need to perform an OPEN against the volume using
something like:
//SOURCE DD UNIT=3390,VOL=SER=AVOLID,DISP=OLD
Any pointers would be appreciated.
My second question relates to 'authority'.
On z/VSE, I have to tell the operating system that I am actually 'DSF'
before it will allow me to issue these CCWs.
Do I have to do something special on z/OS?
Thanks,
Tony Thigpen
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