IBM OS/390 User Manual
5.6.4.1 Accessing a VSE/VSAM Catalog from an OS/390 System
Your migration plan might include the requirement to access VSE/VSAM
catalogs from the OS/390 system.
catalogs from the OS/390 system.
Under no circumstances should you attempt to
share VSAM catalogs or data sets between OS/390 and VSE/VSAM concurrently.
There is no system data integrity provided for concurrent access sharing. Loss of
data may occur. If OS/390 access to a VSE/VSAM catalog is necessary, the
following procedures should be used:
There is no system data integrity provided for concurrent access sharing. Loss of
data may occur. If OS/390 access to a VSE/VSAM catalog is necessary, the
following procedures should be used:
1. Execute the VSE AMS command EXPORT DISCONNECT to disconnect the
VSE user catalog from the VSE master catalog.
2. Execute the OS/390 AMS command IMPORT CONNECT to connect the VSE
user catalog to the OS/390 master catalog.
3. An OS/390 AMS DEFINE ALIAS command may be necessary to reestablish
OS/390 ALIAS name structures for that user catalog.
The catalog and data are now ready to use with OS/390 applications. (Note:
Suballocated VSAM space may be accessed through OS/390 VSAM catalogs.
However, OS/390 VSAM catalogs do not support non-VSAM data sets in VSAM
space; that is, a VSE facility usually used for VSE/VSAM-managed SAM files.)
Suballocated VSAM space may be accessed through OS/390 VSAM catalogs.
However, OS/390 VSAM catalogs do not support non-VSAM data sets in VSAM
space; that is, a VSE facility usually used for VSE/VSAM-managed SAM files.)
″
Reversing
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the above procedure allows VSE access to the catalog once again.
This is accomplished by:
1. Execute the OS/390 AMS command EXPORT DISCONNECT.
2. Execute the VSE AMS command IMPORT CONNECT.
The catalog and data are again ready to use with VSE applications.
DISCONNECT does not prevent access by VSE of OS/390 applications which
already have access to the catalog or data sets defined in the catalog. Care
must be taken in implementing procedures to make sure the catalog is properly
closed in OS/390. In VSE, catalogs are never actually closed, but can be
disconnected to prohibit access. In OS/390, you can find out which catalogs are
open by using the MODIFY CATLOG command. See the manual
already have access to the catalog or data sets defined in the catalog. Care
must be taken in implementing procedures to make sure the catalog is properly
closed in OS/390. In VSE, catalogs are never actually closed, but can be
disconnected to prohibit access. In OS/390, you can find out which catalogs are
open by using the MODIFY CATLOG command. See the manual
Managing
Catalogs, SC26-4914 for more information.
You may also access an OS/390 created VSAM user catalog from a VSE system
by disconnecting the catalog from the OS/390 system and then connecting it to
the VSE system. The procedure is the same as that described above.
by disconnecting the catalog from the OS/390 system and then connecting it to
the VSE system. The procedure is the same as that described above.
Under no circumstances should you attempt to share VSAM catalogs or data sets
between OS/390 and VSE/VSAM such that more than one system can perform
updates concurrently. Read-only sharing may be permitted. See 5.6.6.3,
“Cross-System and DASD Sharing” on page 129 for more detail.
between OS/390 and VSE/VSAM such that more than one system can perform
updates concurrently. Read-only sharing may be permitted. See 5.6.6.3,
“Cross-System and DASD Sharing” on page 129 for more detail.
5.6.4.2 Converting VSE/VSAM Catalogs to OS/390 ICF Catalogs
The OS/390 AMS CNVTCAT command converts a VSAM catalog to an OS/390 ICF
catalog.
catalog.
After you are sure that VSE will not need to access the VSE catalog(s),
they may be converted to ICF format.
Non-VSAM files in VSAM managed space must be deleted before running
CNVTCAT. If the VSAM catalog has VSAM clusters defined in sub-allocated
space, they will be converted to UNIQUE space during the conversion. All
volumes owned by the catalog should be backed up before running CNVTCAT.
See
CNVTCAT. If the VSAM catalog has VSAM clusters defined in sub-allocated
space, they will be converted to UNIQUE space during the conversion. All
volumes owned by the catalog should be backed up before running CNVTCAT.
See
Managing Catalogs, SC26-4914, chapter 9 for more detailed information.
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VSE to OS/390 Migration Workbook