I want the datasets created on disk to have the same name they have on
tape (as is stored in the tape label). I know what these names are, and
they are compatible with our DASD datasets naming standards.
Why cannot DITTO (or other utility program), just read each tape dataset
label, allocate a disk dataset with the same name, copy, and then
proceed with next label, continuing this way until EOV is reached).
There are a couple of issues:
1) tape labels have room for only 17 characters of the dataset name (a
hold over from operating systems prior to OS/360). Although you can
open tape datasets using a 44-character name, only the last 17
characters of the name are stored in the tape label. Only names of 17
characters or less are completely stored in the label. If you have a
tape management system, and the tape is recorded in that TMS, then the
full 44-char name is stored in the TMS database and is verified at OPEN
time; otherwise, only the last 17 chars in the label is compared to
whatever you provide.
The point is that if the dsnames are longer than 17, then DITTO or
whatever has no idea what the beginning of the name is, and can't
allocate the dataset.
Innovation's tape utility FATAR has interfaces to the popular TMSs to
get the full dataset name if available, but it doesn't support tape to
disk copy.
2) how big to allocate the disk file. The tape header records give no
clue as to the size of the tape datasets, 1 record, a million records,
or whatever.
--
Bruce A. Black
Senior Software Developer for FDR
Innovation Data Processing 973-890-7300
personal: [EMAIL PROTECTED]
sales info: [EMAIL PROTECTED]
tech support: [EMAIL PROTECTED]
web: www.innovationdp.fdr.com
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