But to get back at the original question many (12+ years) years ago I
thought that is why IBM came out with the minimal init in ICKDSF. At
least that is what one CR told me when we went through the 3380 to
3390 conversion. Ever since I have been using that before releasing
drives back to the vendor.
Careful. MINIMAL INIT (INIT with NOVALIDATE) just writes the VTOC, and
does not erase any data.
MEDIAL INIT (INIT with VALIDATE NOCHECK) overwrites every track, but we
have traced the I/O and it is particularly inefficient. It actually
reads each track (why? to validate that it has a standard HA and R0),
then reformats the track with a standard R0 (so why did it validate
it?). The WRITE R0 CCW implicitly erases the rest of the track (which
may or may not actually overwrite data depending on the vendor). This
is one track at a time.
MAXIMAL INIT (INIT with CHECK(n) ) overwrites each track one or more
times (n) before doing the WRITE R0 but I don't think it is permitted on
most modern disks.
--
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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