AIX 5.1 ML7 maintenance introduced a new vmtune option, -H, to tune
sequential readaheads. Our data base folks back up data bases by
shutting them down, using the cp command to copy then to a different
directory, then restart the data base and backup the copy.  The -H
default, 0, caused the copy steps in the above process to take twice as
long wall clock.  AIX support recommending setting this parm to 32 which
return wall clock times back to previous levels.

Is there any guidance on what vmtune -H should be set to on my AIX box
running TSM Server?

David Ehresman
University of Louisville