No. The "default 5" is for tape datasets.
For DASD the default is just 1. Of course things like VOL count, UNIT
count or DVC may change it.
However it's quite easy for SMS-managed datasets - just type the number
(in VOL or DVC). But for nonSMS-managed ones you need to provide volume
serials and/or play with mount parameters (public, storage, private).
Last but not least the volumes have to exist - there is no big deal with
VOL(,,,30) and environment with 10 volumes available.
--
Radoslaw Skorupka
Lodz, Poland
W dniu 21.12.2025 o 22:49, Mike Schwab pisze:
VOLUME has a default count of 5. Specify 6-255 or a STORCLAS with a
higher VOLUME count.
https://www.ibm.com/docs/en/zos/3.1.0?topic=vp-subparameter-definition
https://www.ibm.com/docs/en/zos/3.1.0?topic=statement-unit-parameter
On Sat, Dec 20, 2025 at 12:48 PM Peter
<[email protected]> wrote:
Hello
A general question
A non-sms dataset cannot span over volume count of more than 6 ?
Cause I was able to allocate using ISPF 3.2 dataset on 11 mod27 but the job
failed with the below error spanning not more than 6 volumes.
I used IDCAMS repro to copy
IEC032I E37-08 , IFG0554P.
On Sat, 20 Dec 2025, 20:24 Radoslaw Skorupka, <
[email protected]> wrote:
W dniu 20.12.2025 o 01:08, Michael Watkins pisze:
From memory: No z/OS dataset can span more than 59 volumes. 16 extents
can reside on each volume unless the data set is SMS-managed and the
DSNTYPE is defined as 'EXTENDED', in which case up to 123 extents can
reside on each volume. However, unless Extent Constraint Removal is
specified as 'Y' in the DATACLAS, the total number of extents spanning all
volumes is 255.
Not exactly.
Datasets are limited to 16 or 123 extents per volume.
Some datasets can be multi-volume, other datasets are single-volume
only. Maximum is 59 volumes (on DASD).
Some datasets are limited to 64k TRK per volume, other are not limited.
The limits depends on dataset organisation and type. Examples:
basic PS - 16 ext, 59 vol, 64k TRK
large PS - 16 ext, 59 vol, 16M TRK
extended format PS - 123 ext, 59 vol, no known limit for size.
PDSE - 123 ext, 1 vol, no practical limit for size.
VSAM - 123 ext, 59 vol, 4GB limit size (with exception for ZFS)
ext-fmt & ext-addr VSAM - 123 ext, 59 vol, 4G CI size (up to 128 TB),
other interesting features.
(the above is not full list)
SMS is pre-req for extended format, however as we can see it is not
pre-req for 123 extents.
Extent constraint removal is for VSAM only and for VSAM-specific limit
(255 ext per dataset or rather component).
--
Radoslaw Skorupka
Lodz, Poland
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