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Notes:
Tuning is requested for MVS via the TUNE=MVS parameter, the change from 3380
to 3390 disks is indicated via the DEV parameter.
The user is able to plan the new operating system and DASD requirements even
before a decision to convert is made.
The Data CISIZE increases from 14336 to a more efficient 18432, which causes
a change in physical record size from 7k to 18k.
In addition to tuning for increased track capacity (3390=55k, 3380=46k) the
file is tuned to improve performance. The new Allocation of CYL(106 14),
ensures that the primary allocation is large enough to accommodate all of the
records currently in the file.
Tuning for a 3380 would have given the larger value of CYL(127 16). Thus
tuning for the new disk device ensures the user does not waste disk space
when changing DASD.
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