#varyoffvg

ok, so you've done the tweaks mentioned in part 1 but job performance is still poor, what next?

you will have to increase the queue_depth of your disks.  queue_depth determines how many requests can be sent to your disks at any one time.  the larger the queue, and increasing it can increase disk I/O throughput

you will first need to figure out what your current queue_depth is set at:

# lsattr -El [pv_name]

you'll then have to figure out what you want to change it to.  i would say try doubling or tripling it at first, then monitor your job again and see what your %tm_act is at.  you do want it so that there's some activity on the %tm_act but not in such a way that it's consistently high

changing the queue_depth, however is a disruptive change and you will want to change it to all the pv/disks that are in the vg you're trying to tune:

# varyoffvg [vg_name]

# chdev -l [pv_name] -a queue_depth=[new_value]