For DR security purposes, format writing any kind of data will
cause the rest of the track to be erased after the last block is written
and, when read back by software on the mainframe, the original data will not be
readable. In this case it doesn't matter if you write two, three, 50, or one
block per track of only one byte long. What matters is you are doing format
writes, as would be the case with DISP=NEW. Still it will require one whole
revolution's worth of time for each track to be erased.
It doesn't necessarily require a revolution. Depending on how the disk
vendor has written their CKD emulation, it may simply be necessary to
write info at the beginning of the emulated CKD track (on the FBA disk)
indicating that there are no more records on the track. Residual data
may still exist on the rest of the emulated track, but there is no way
to access it from the mainframe. The only way to ensure the complete
overwrite is to write a full-track record.
--
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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