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Data
space usage on VSE has grown since it was first introduced on VSE with
more IBM and vendor products utilizing it. VTAM uses data spaces for
communicating with VTAM based application such as CICS and others. CICS
Transaction Server uses data spaces for CICS Data Tables used for
loading VSAM files in memory and for CICS Data Management Facility (DMF)
used for statistics and monitoring data recording. The VSE Basic
Security Manager (BSM) uses data spaces for holding security information
in memory. Many vendor products such as sorts and other monitoring
products use data spaces to perform their functions faster.
With
all these uses of data space it is important to monitor the availability
and use of data spaces in the VSE system. Implementation of a new
product or adding function that uses data space may cause the available
data space or type of data space available to be exhausted and produce
errors. VSE provides the QUERY DSPACE command to monitor data space
definitions and usage.
The
QUERY DSPACE command without any options shows a summary of the current
system data space definitions and usage. The following is an example of
that command:
query dspace
AR 0015 DSIZE MAX
PARTMAX COMMAX VDISK DFSIZE
AR 0015 DEFINED: 49152K
256 16 5 1 960K
AR 0015 ACTUAL: 16480K
9 3 4 1
AR 0015
AR 0015 AREA DSPS AREA DSPS AREA DSPS
AREA DSPS AREA DSPS AREA DSPS
AR 0015 BG 1 FB 3 F3 3
W1 2
AR
0015
AR 0015 1I40I READY
The
‘DEFINED:’ row shows the system definitions last set by the SYSDEF
command. This command is typically included in the ALLOC or $0JCL IPL
procedure to set system maximums for data space definitions. The SYSDEF
command can be entered anytime after IPL to change most of these
settings. The command defines the maximum total data space than can be
allocated for the system (DSIZE), maximum number of data spaces (MAX),
maximum number of partition data spaces (PARTMAX), maximum number of
type COMMON data spaces (COMMAX), number of virtual disks and a default
size for the DSPACE parameter on the EXEC JCL statement. The ‘ACTUAL:’
row shows the actual amount of data space in use and how many. The query
also shows a summary of number of data spaces allocated in partitions.
If any of the ‘ACTUAL:’ values equal the “DEFINED:’ values then you may
need to increase your settings on the SYSDEF command.
The
QUERY DSPACE,ALL command is useful for determining how much data space
is allocated to specific partitions, to virtual disk or to other
facilities. The following shows and example of this command:
query dspace,all
AR 0015 AREA
DSPNAME SIZE MAXSIZE SCOPE OWNER DU-AL PASN-AL
AR 0015
SYSIVFDF 1440K 1440K COMMON BG X
AR 0015
BSMSPACE 960K 960K COMMON FB X
AR 0015
BSTSPAC1 960K 960K COMMON FB X
AR 0015
BSTSPAC2 960K 960K COMMON FB X
AR 0015
ZIPPER 1000K 1000K COMMON W1 X
AR
0015
AR
0015 F2 IST8A435 2048K 2048K ALL F3 X
AR
0015
AR 0015 F3
IST5754F 1024K 2048K ALL F3 X
AR 0015 F3
IST8A435 2048K 2048K ALL F3 X
AR 0015 F3
IST54BAD 2048K 2048K ALL F3 X
AR 0015
AR 0015 T1
IST54BAD 2048K 2048K ALL F3 X
AR
0015
AR 0015 W1
ZIPCTLS 6000K 6000K ALL W1 X
AR
0015
AR 0015 1I40I
READY
The
SCOPE COMMON data spaces are typically for system or vendor product
functions and can sometimes be identified by the data space name (DSPNAME)
listed in the query. For example, SYSIVFDF is the data space for virtual
disk FDF defined with the VDISK command. The data spaces BSMSPACE,
BSTSPAC1 and BSTSPAC2 are data spaces used by the VSE Basic Security
Manager. ZIPPER is a data space used by illustro’s z/IPMon product.
The
query also identifies data space allocation for each partition. This
shows how much is currently allocated (SIZE) and the maximum that can be
allocated (MAXSIZE). The latter is based on the DSPACE parameter of the
EXEC JCL statement for the job running in that partition or the DFSIZE
if no DSPACE parameter was coded on the EXEC JCL statement. If the SIZE
value equals the MAXSIZE value then you may need to increase your DSPACE
setting on the EXEC JCL statement if out of data space error messages
start occurring.
Each
data space will have a unique data space name. Note that partition F3
has three data space names but two of these are the same as the ones in
partition F2 and T1. These are not separate data spaces but actually are
created when partitions F2 and T1 started. Partition F3 is the VTAM
partition and always lists the data space names of the VTAM based
partitions with which it uses data space names to communicate, in this
case F2 and T1. The amount of data space allocated in the VTAM partition
F3 is the one with data space name IST5754F and would be the one to
monitor for setting the DSPACE parameter on the EXEC JCL for the VTAM
partition.
By
monitoring data space usage with these commands, you can ensure you have
adequate data space and virtual storage available to meet your data
space needs.
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