IBM OS/390 User Manual
VSE/ESA Version 2.2 included new VSAM support for compression of VSAM data
sets. The implementations of the two VSAM systems are not compatible, due to
the differences between VSAM catalogs used by VSE, and ICF catalogs used by
OS/390. COMPRESSED data sets defined in VSE will have to be unloaded from
VSE and reloaded in OS/390. REPRO or EXPORT/IMPORT can be used for this
unload/reload function.
sets. The implementations of the two VSAM systems are not compatible, due to
the differences between VSAM catalogs used by VSE, and ICF catalogs used by
OS/390. COMPRESSED data sets defined in VSE will have to be unloaded from
VSE and reloaded in OS/390. REPRO or EXPORT/IMPORT can be used for this
unload/reload function.
VSAM CISIZEs and Record Sizes
Both VSE and OS/390 VSAM will select an acceptable CISIZE if none has been
specified. If an unacceptable CISIZE has been specified on the DEFINE, both
VSAMs will attempt to select an acceptable default. Refer to the manual
DFSMS/MVS Using Data Sets, SC26-4922, for more information regarding OS/390
VSAM CISIZEs.
specified. If an unacceptable CISIZE has been specified on the DEFINE, both
VSAMs will attempt to select an acceptable default. Refer to the manual
DFSMS/MVS Using Data Sets, SC26-4922, for more information regarding OS/390
VSAM CISIZEs.
You will not be able to directly read a VSE/VSAM KSDS that was created with
index CISIZEs that are
index CISIZEs that are
invalid for OS/390 VSAM. You must EXPORT or REPRO
the cluster from the VSE system and IMPORT or REPRO it into the OS/390
system.
system.
The physical record size is determined during the DEFINE or data set allocation
by an algorithm that includes CISIZE and DASD device characteristics. The
physical record size will always be equal to or less than the CISIZE. One or
more physical records will contain a control interval. Beyond that, VSE and
OS/390 use different algorithms.
by an algorithm that includes CISIZE and DASD device characteristics. The
physical record size will always be equal to or less than the CISIZE. One or
more physical records will contain a control interval. Beyond that, VSE and
OS/390 use different algorithms.
OS/390 uses one algorithm for data sets that are cataloged in VSAM catalogs,
and another for data sets that are cataloged in ICF catalogs. The VSE and ICF
algorithms are similar until the CISIZE exceeds 8K. VSE will not create a physical
record size greater than 8K for VSE/VSAM releases prior to VSE/ESA 1.3.
VSE/VSAM in VSE/ESA 1.3 permits physical record sizes up to 30,720 (30K)
bytes, depending on device type and Control Interval size specified. The OS/390
algorithm used with VSAM catalogs will not create a physical record size greater
than 4K.
and another for data sets that are cataloged in ICF catalogs. The VSE and ICF
algorithms are similar until the CISIZE exceeds 8K. VSE will not create a physical
record size greater than 8K for VSE/VSAM releases prior to VSE/ESA 1.3.
VSE/VSAM in VSE/ESA 1.3 permits physical record sizes up to 30,720 (30K)
bytes, depending on device type and Control Interval size specified. The OS/390
algorithm used with VSAM catalogs will not create a physical record size greater
than 4K.
In summary, to be sure you obtain the CISIZE you want, you should explicitly
specify the size; that is, not take the default. For data sets where
incompatibilities exist, you will need to EXPORT or REPRO the data set from the
originator system and then IMPORT or REPRO it into the destination system.
specify the size; that is, not take the default. For data sets where
incompatibilities exist, you will need to EXPORT or REPRO the data set from the
originator system and then IMPORT or REPRO it into the destination system.
VSE/VSAM-managed SAM Files
VSE SAM files in VSAM managed space (SAM/VSAM) are not supported by
OS/390. OS/390 cannot access them. They may be converted to VSE or OS/390
Sequential Access Method (SAM or QSAM) data sets. With OS/390, specific track
or cylinder addresses for allocation are not required as they are for VSE SAM.
OS/390. OS/390 cannot access them. They may be converted to VSE or OS/390
Sequential Access Method (SAM or QSAM) data sets. With OS/390, specific track
or cylinder addresses for allocation are not required as they are for VSE SAM.
The files may be ported to OS/390 by copying them to a sequential data set (tape
or DASD) using a VSE utility such as DITTO. The OS/390 utility, IEBGENER, may
be used to copy them under OS/390. Many VSE SAM/VSAM files are used for
temporary (work) data sets. These need not be converted as their contents will
not be ported to the OS/390 environment.
or DASD) using a VSE utility such as DITTO. The OS/390 utility, IEBGENER, may
be used to copy them under OS/390. Many VSE SAM/VSAM files are used for
temporary (work) data sets. These need not be converted as their contents will
not be ported to the OS/390 environment.
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VSE to OS/390 Migration Workbook