[KLUG Members] RS6000

[Adam Williams]

>Ok, this is slightly off kilter being an AIX issue, and targeted at
>Adam.

I feel special. :)

>But, we all learn from listening and maybe else has some input
>here.  I am having some performance issues with my AIX box.  It is an
>IBM RS6000 604e at 332Mhz (43P Model 140).  I don't have any experience
>with Motorola processors and don't know what to expect from it.  It is

There is no apples-apples comparison of RS/6000 arch to ix86 arch based
upon MHZ, etc....  For the most part you should get much better
performance from an RS/6000 box of the same MHZ as you would from a x3 MHZ
ix86 box assuming you doing I/O intensive processes, are using good SCSI
equipment and your r/w load is correctly balanced.  For I/O PC-ish stuff,
even low-end IBM Netfinites, can't even ***DREAM*** of touching the kind
of load an RS/6000 can carry all day.

A 604e is old in PC terms,  but not terribly so.  In terms of RS/6000
lifespan it is pretty young.

>running our accounting package on a progress database.  It also has
>loaded EGB gateway software to tie from progress to Microsoft SQL
>server.  We only have around 12 users that access the accounting

Amount of RAM?

>software and only when a web pricing (on average 20 accesses per day)is
>requested does it tie back to retrieve data.
>So here are the questions:
>1. What do I use for benchmarking performance

Basically the same tools you'd use for Linux: top (or called "monitor
-top" on AIX), vmstat, iostat, etc...

>2. What should theses values be.

Priority one is to try and balance and interleave your I/O.  If you are
not using hardware RAID and have a heavy read load (who doesn't) you might
want to think about soft-mirroring your data LVs on seperate drives.   Use
the outer three quarters of the drives capacity and the center 25% for
archives, libraries, etc...

Use vmstat to look for paging, paging is bad, as always.  Most production
machines always page-burst at least a couple of times a day,  not matter
how much RAM you dump in the things.  If your like us (idle, idle, Oh!
it's 3pm - CRUNCH!!!, idle, idle) page to a couple of drives on a seperate
SCSI channel if at all possible.  If a process needs to page in it gets
suspended and the OS context switches to other processes until the pages
are in-core.  Context switches on industrial strength operating systems
(AIX, HP/UX, Windows 2000/XP) cost alot!  Interestingly that is one of the
reasons Linux can often best them on "equivalent" hardware for small
installations,  but dump 32,000+ I/O-ing threads in there and Linux* rolls
over like an old dog.  (Of course, the thought of Win2000 with 32,000
threads is pretty funny,  but for other reasons.)

*The stock kernel anyway,  it can be "tweaked".

Use iostat to make sure you aren't dumping all your load on a single
drive.

> 3. If I need a new RS6000, what would be a good recommendation. >

p640.  Oh, so swwwweeeeeeeettttttt.......