There are redbooks and whitepapers out there that give you a reasonable rule
of thumb to at least get you started. Following those books/papers will
work but they are a bit more than what most need to make it all work. Once
you get more familiar with the environment and the applications, adjustments
can be done to reduce resources.
It will also depend on the version of WAS you use - V6.1 is much better on
resources on multiple shared environments than V5. Memory usage for V6 may
seem higher for "one app/jvm" servers but add jvms and resources are used
more efficiently. Running in 31bit or 64 bit make a difference too.
Remember - most times LESS is better. Too much memory is not a good thing.
Running the servers on the LEAN side is a Good Idea. Using the Swap devices
is a Good Thing. Over using them means some adjustments are probably
needed.
For reference this is what we generally do:
Because of security rules, we have our Internet facing servers on a
different LPAR from the application servers. The Intranet servers live in
the same LPARs as application and database servers. We don't mix the IHS
and WAS _images/applications_ on the same server(s) at all. Again, for
security they want interface, application and data layers 'separated'.
By default our WAS servers have 1G of virtual memory but they are averaging
2G or more now and go up to 8G. The memory size is going to depend on what
is in the server, the size of the jvm(s) and how mature the application is
(no memory leaks, etc.)
For swap disks we define two VDISKs and one minidisk. For a 1G machine we
set each VDISK at 64M and the MDISK to 384M. So rule of thumb is half the
memory size total with at least one VDISK as the priority swap device.
WAS is clustered for apps that want high availability so yes we do cluster
our WAS servers.
Jim Vincent
On 3/30/07, Jon Brock <[EMAIL PROTECTED]> wrote:
(I am cross-posting this message to the linux-390 and IBMVM lists.)
We are going to be getting into using WebSphere and HATS at my
shop. We have 1 IFL running VM, with Linux guests. Most of the
configuration information I have seen presumes standalone boxes rather than
a virtualized environment. I have a couple of questions for those of you
who run WAS on Linux under z/VM, or at least those of you who are inclined
to answer:
Do you run your web server(s) on the same image as your WebSphere app
server or use a separate image strictly for the web server?
How big do you make your WebSphere images; that is, how much virtual
storage do you assign in USER DIRECT? How much swap space do you give
them?
Do you cluster your WAS images?
Thanks in advance for any information.
Jon
