Re: Main Storage on new models

[Larry Bolhuis <lbolhuis@xxxxxxxxxx>]

The system model has little to do with the memory required. In other words, 
"It's the workload stupid!" If the load on the system will go up significantly 
or the workload will be changing, then more memory could be required. For 
example adding Domino or Websphere workloads would make a serious dent in your 
2GB of storage. Significant Apache loads also affect memory requirements.

I can't see that moving to ESS matters at all. The iSeries sees Shark as if it 
were disk volumes of 8, 17, 35, or 70 GB. Each FC #2766 Fiber Disk 'sees' up 
to 16 (AIRC) disk units 'created' by ESS.  This is essentially no different 
than using SCSI controllers such as FC #4778 or FC #2757. These units see up 
to 15 or 18 units respectively. Just like 'real disk' you may need more than 
one FC #2766 for proper performance. If the BP says "One will do, just create 
bigger LUNS!" then you may well need memory to help out that overloaded 
controller. Properly designed, however, there should be no difference.

If you need to upgrade from V4R5 to V5R2 then some additional memory might be 
a good idea but if your faults are what you indicate then I can't imagine how 
quadrupling the memory can be justified.

 My .02

  - Larry

Ingvaldson, Scott wrote:
> We are in the process of getting quotes on a new 810-2466/7409 to replace an
> aging 620.  The 620 has 2 GB of main storage.  One BP is telling us that 2
> GB will be fine in the new 810, another is saying they would recommend 8 GB
> (at a cost of $25,000!)
>
> They say that the additional memory is needed due to the new model and the
> possibility that we may be moving to ESS (shark) external DASD on the new
> box.
>
> We don't have any apparent memory constraints on our current box, less than
> 20 faults/second on average.


--
Larry Bolhuis           | IBM Certified Solutions Expert
Vice President          |     iSeries Technology V5 R2
Arbor Solutions, Inc.   |     e-business for AS/400 V4 R2
(616) 451-2500          | IBM Certified Specialist  AS/400
(616) 451-2571 -fax     |     RPG IV Developer
lbolhuis@xxxxxxxxxx     |     System Administrator for OS/400 V5R2
www.arbsol.com          |     Professional Network Administrator
                        |       Network/Multiple Systems
                        |     Client Access