Re: How to estimate amount of memory to assign to a memory pool

[Jim Oberholtzer <midrangel@xxxxxxxxxxxxxxxxx>]

While I appreciate the IBM i performance adjustment function quite a 
bit, it's far from foolproof, and I am finding quite a few of my 
customers turning it off.

If you are not using performance adjustment, don't turn it on just for 
this, that could cause a long list of unintended consequences.  If you 
are using the performance adjustments, then you might  consider using a 
separate storage pool as you suggested, but tune the shared pool with 
WRKSHRPOOL then F11 until you can set the priority and maximums for that 
pool.  That way you can allow the performance adjustment to work, while 
throttling back the process that should be mostly I/O if I ready your 
email correctly.

At  V7 of IBM i you can do workload groups, but that is not granular 
enough (only down to one processor) for 99.5% of the performance tuning 
scenarios that most folks run into since most LPARs are less than one 
processor  or only one processor to start with.

Jim Oberholtzer
Chief Technical Architect
Agile Technology Architects


On 6/26/2012 2:23 PM, sjl wrote:
> Richard -
> If they have the system set up for automatic performance adjustment, I would
> set it low and let the system auto-tuner adjust it.
> - sjl
>
> Richard wrote:
> I have a job that migrates spool file images from a jukebox to Dasd.  My
> thought is that I should segregate this job from the normal system processes
> so as to avoid any possible resource contention as I cannot affect the day
> to day running of the companies where these migrations will be occuring.
> That said, I created a new single threaded sub system.  When assigning a
> memory pool, how do I go about calculating the storage size?
>
>
> --