|Attributes Defined in SYS1.NUCLEUS(SYSCATxx)
- Master catalog's volume
- Master catalog type
- SYS% facility on or off
- Multilevel alias search level
- Catalog address space service task lower limit
- Master catalog name
- Tape volume catalog high level qualifier
- AUTOADD indicator
- CAS Service Task Table Size (TASKTABLESIZE)
Once you have defined your master catalog, and have cataloged the
necessary system data sets in it, you must identify the master catalog
to the system to use it as a master catalog. The SYSCATxx member
of SYS1.NUCLEUS contains the information for identifying the master
catalog to MVS™.
If you use the LOADxx member to identify
the master catalog, the system uses the master catalog specified in
the member, and the master catalog message is not issued.
You can have multiple SYSCATxx members.
The default name is SYSCATLG. Each copy of the SYSCATxx member
can identify different master catalogs.
The following is the format of the SYSCATxx
of SYS1.NUCLEUS (the member can contain only one record):
is the volume serial number of the master catalog's
volume. This must be in the first 6 bytes of the record.
- catalog type
the catalog type and SYS% facility default, where:
- blank or 0
- Indicates a catalog master catalog. In this case, leave bytes
8, 9, and 10 blank. Only the volume serial number and the catalog
name can be specified for a master catalog.
- indicates a catalog, with the SYS% facility turned off,
- indicates a catalog with the SYS% facility turned on.
This value must be defined in the seventh column
of the record. The setting for the SYS% conversion facility can be
changed after IPL for a current session with the MODIFY CATALOG,SYS%
- alias level
specifies the multilevel
alias search level. The default is 1 and the maximum is 4.
value must be defined in the eighth column of the record. If you want
the default value of 1, either specify 1 or leave the eighth column
This value can later be changed for a current session
with the MODIFY CATALOG,ALIASLEVEL operator command.
- CAS task low limit
specifies the catalog address
space service task lower limit (maximum number of CAS service tasks
or requests), in hexadecimal. The value can range from X'18' to X'FF',
but the default is X'3C'.
This value must be defined
in the ninth and tenth columns. Specify the default value (either
explicitly, or by leaving these two columns blank). If the catalog
address space needs more services tasks, it creates them.
- catalog name
specifies the name of the master catalog. The
name can be up to 44 characters.
To change to a different master
catalog, you must IPL the system and specify a different SYSCATxx member.
- tape volume catalog high level qualifier (optional, otherwise
specifies the first name qualifier of all volume catalogs
(volcats) in the system. The value is specified as 1 to 8 characters.
See Defining Names for a Tape Volume Catalog. Leave this blank if you have
no tape volume catalog member.
- AUTOADD feature (optional, otherwise blank)
the autoadd function is enabled when the first connection is made
to the coupling facility by the catalog address space.
value Y must be specified in column 63 of
- TASKTABLESIZE (optional, otherwise blank)
is a three-digit
decimal number that specifies the size of the service task table
allocated by CAS in common storage. The maximum value is 400.
If no value is supplied, or the value supplied is less than 200,
a value of 200 is used.
- 10% of the service tasks specified are reserved for system use,
such as recursive catalog calls resulting from the need to allocate
catalogs for a request. The remaining service tasks are available
for user catalog requests.
- This parameter cannot be specified in the SYSCAT entry of a LOADxx member.
TASKMAX, which you can specify in parmlib member
IGCATxx or the Modify Catalog command, differs from this value
in that it is a soft limit on the maximum number of concurrent
non-CAS service requests that can be running at any given
time and can be changed at any time. TASKTABLESIZE, on the other hand,
can only be changed with an IPL. TASKMAX can be no larger than
90% of TASKTABLESIZE.
following is a sample step to create the SYS1.NUCLEUS member SYSCATLG.
This job describes a master catalog named SYS1.MASTERA.ICFCAT on volume
SYSRES. The SYS% to SYS1 conversion facility is turned off. The multilevel
alias search level is set at one. The catalog address space service
task lower limit default of X'3C'
is used by leaving columns
9 and 10 blank.
//SYSCAT EXEC PGM=IEBGENER
//SYSPRINT DD SYSOUT=A
//SYSIN DD DUMMY
//SYSUT2 DD DSN=SYS1.NUCLEUS(SYSCATLG),DISP=SHR,DCB=(RECFM=U)
//SYSUT1 DD *
SYSRES11 SYS1.MASTERA.ICFCAT y