On 22 April 2013 11:54, R.S. <[email protected]> wrote:
> Scenario: z/VM owns some CKD volumes, more volumes are available, remaining
> volumes are empty, but formatted for use with MVS.
> The goal is to connect one of the remaining volumes to z/VM and format it
> with given label. The space shall to be available for user space
> (minidisks).
> No HCD/IODF activities are necessary.
>
> What utility should be used? ICKDSF or CPFMTXA?
> What command?

Either will do what you need, but for a decade or more now, CPFMTXA is
just a front end to ICKDSF, so you may as well use it directly. Last
time I looked, the z/OS ICKDSF does not have the needed commands to
manage a VM volume, so you have to run it on VM (or in theory,
standalone).  But ICKDSF is probably familiar to MVS sysprogs.

You need to write an allocation map (to ensure CP doesn't accidently
use any of the volume for things like paging/spooling), and a dummy
VTOC with all space allocated (to discourage any z/OS system that may
happen to see the volume), and maybe a volume label (or most likely
that's already done). All this is done by formatting cylinder 0, track
0. There is no need to format any other parts of the volume unless you
need to erase existing data. Normally each minidisk user will format
their own portion upon first use, so your formatting it would just be
lots of unnecessary I/O.

In all cases, of course, you must have the device ATTACHed to your
virtual machine, though the virtual address does not matter.

For ICKDSF:
Invoke by entering ICKDSF CONCOLE CONSOLE (or let it prompt you). Then:
CPVOLUME FORMAT UNIT(uuuu) NOVERIFY VOLID(newvol) RANGE(0,0)

You can check the state of an existing volume with CPVOLUME LIST . And
you can/should use VERIFY if your volume is already labeled and you
want to be sure you are pointing at the right place. Also caution -
RANGE default is 0-END, so while it will work, it will waste time and
I/Os.

For CPFMTXA:
CPFMTXA uuuu newvol FORMAT 0 0

and then watch it invoke ICKDSF.

The bad news: This is all from memory...

Tony H.

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