why RCLSTG

We're preparing to add some 5065 disk towers full of 17.5 GB drives to our
740 12-way dinosaur to replace legacy disk, and we'll be adding memory as
well.  We'll be adding the new drives to the ASP and then removing the old
disk via DST, allowing the system to pump the old disks' data to the new
drives that remain in the pool.

Our CE told us to perform a RCLSTG and a long IPL before the hardware
installation.  The last RCLSTG in April took about two hours.  We started
one this weekend and it showed no sign of finishing after three and a half
hours in the midst of a critical processing cycle, so operations called
support for directions on how to end the RCLSTG.  We're estimating that the
RCLSTG would run for another six hours or so.

So many upgrades require a RCLSTG.  I'm trying to figure out why.  I think I
can understand why OS upgrades and certain PTF packages require a RCLSTG,
but I'm not clear on why we would need to RCLSTG before adding disk and
migrating RAID sets.  We don't really have time for both a full system save
and a RCLSTG before the installation, and I'm definitely not blowing off the
save.  I'd like to know if there are concrete risks associated with not
having performed RCLSTG before a hardware upgrade of this type.

The only CE I have available at the moment is one of the ones who was
cross-trained from the RS/6000 and who seems to only know the AS/400
phonetically.  Any insight anyone could offer would be greatly appreciated.

Much thanks...

James P. Damato
Manager - Technical Administration
Dollar General Corporation
<mailto:jdamato@dollargeneral.com>