Re: Disk requirement (performance-wise) on a Power 7 replacing a System i 520

V5R2 will support a minimum of 70GB as a load source. Since you hold on
to your systems for quite some time I think I would go for something even
bigger. Probably the 280s. Maybe the 140's. Since you are raiding you
are going to want them all the same size. It's cheaper to add more 280's
than it is to add another 5887, or to rip out smaller drives and replace
with larger drives when you hit a capacity boundary.
With your low disk performance requirements you just may get by with 5
drives (with the 5th one for hot spare). Remember one drive is lost to
raid striping. Four 280's will look like four 210's after the raid
striping.
If you have plenty of slots available it's always easier to expense more
disk in if it turns out you have a disk performance issue.
I also agree that spending money on the memory is a good idea. We have
one machine where we can't physically add more memory and we're chasing
quotes on an upgrade. If there's even a remote possibility that WAS
and/or Domino may be on your horizon get memory. Had a consultant today
who couldn't get a WAS installation to even work since it didn't have
enough memory and I had to dlpar more memory out of a different lpar.
Wouldn't be the first consultant I've had to do this with for a WAS
installation. The other one had us.ibm.com in his email address.


Rob Berendt