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VSE/VSAM-managed SAM files
− Default models
− NOALLOCATION data sets
− Implicit JCL DEFINE
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Reusable data sets
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Partition independent file names
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VSE/VSAM BACKUP/RESTORE and VSE FASTCOPY
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IKQVDU - volume cleanup
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IKQVCHK - catalog check
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Space classes
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VSAM SHAREOPTIONS (SHR(4) and SHR(4 4) differences)
5.6.5.2 FBA DASD
Fixed Block Architecture (FBA) DASD devices such as the 3370, 3310, 9332, 9335,
9336, and FBA virtual disks are not supported by OS/390. Any data sets on these
devices must be moved to an OS/390 supported Count Key Data (CKD) or
Extended CKD (ECKD) DASD device such as the 3390, 3380, 3350, or 3375. This is
generally done by copying the data sets to tape and loading them down with
appropriate OS/390 utilities. For VSAM data sets, AMS REPRO is recommended.
5.6.5.3 Catalog Structures
NOIMBED Option
VSE/VSAM catalogs may be defined with the NOIMBED option. This saves DASD
space by not replicating the sequence set in the data portions of the catalog. It
may make a catalog search take longer an a CKD device. These catalogs
cannot be accessed by OS/390 VSAM.
The procedures for converting these back to IMBED format are described in the
VSE/VSAM Programmer
′
s Reference
, SC24-5145. Briefly, EXPORT all files, delete
all VSAM space, delete the catalog, redefine the catalog with the IMBED option,
re-define the VSAM space, and IMPORT the files. If VSE/VSAM BACKUP is used
instead of EXPORT, then RESTORE is used instead of IMPORT. BACKUP and
RESTORE should be both easier to use and faster than EXPORT and IMPORT.
The above paragraphs are talking about a VSAM catalog being accessed by both
VSE and OS/390 but when the catalog is converted, NOIMBED and NOREPLICATE
are recommended when behind cache. IMBED is not recommended for VSAM
data sets or ICF catalogs when these data sets are stored on DASD volumes
behind a cached control unit because IMBED implies replication and replicated
data can result in poor cache usage. If sufficient real and virtual storage is
available, and appropriate BUFNI values are specified to keep the index
components for VSAM clusters in storage, NOIMBED and NOREPLICATE is also
indicated, even with non-cached DASD hardware.
Shared Volume Ownership
VSE or OS/390 VSAM catalogs may own space on more than one DASD volume.
Only one VSAM catalog may reside on a volume. Both VSE and OS/390 VSAM
120 VSE to OS/390 Migration Workbook