zLinux: RHEL on IBM mainframe

[Shawn Wells]

Kenneth Holter wrote:
> Hi.
>
>
> Does anyone have experience with running RHEL on IBM mainframe? In
> particular, I'm curious about what implications this has for the linux
> system administration part of it, such as these:
>   
Hi Kenneth,

    I'm the lead solutions architect for Linux on System z at Red Hat -- 
feel free to ping me offline.


>    - Whick package repositories are available?
>   
Pretty much all of them.  The largest difference is that there is not 
GFS or RHCS at this time.

>    - Are there any EPEL-like repos for zLinux?
>   
Yes.

>    - Can we use our Red Hat Satellite Server to manage packages for zLinux?
>   
Yes.  The largest catch is when you do provisioning -- you'll need to 
assign the virtual machine resources through z/VM, then upon your first 
IPL you can connect into satellite.

>    - Are there many tweak and issues I need to be aware of?
>   
Slight command differences, fdasd versus fdisk kind of things.  Memory 
management is also completely different -- a 64mb allocation of memory 
suites many peoples needs.

> We currently have quite a few RHEL servers based on x86 hardware, so I'm
> basically interested in what kind of changes/adjustments I must implement
> to add IBM mainframe to our list of hardware platforms. Please let me know
> if there are other mailing lists that are more suitable for this topic.
>
>   
If you have an option, run the RHN Satellite off the Mainframe.  When 
it's on the Z it can utilize hipersockets -- a network stack in memory 
-- for high throughput.  15-30 second provisioning can be achieved.  It 
will still manage distributed boxes in the same way.

If looking at this from an economical standpoint, your consolidation 
ratio makes or breaks the business case.  RHEL for System z is offered 
on a per-IFL subscription basis with unlimited virtual machines.  At one 
customer they run ~55 virtual machines per IFL on a z9, but do note 
they're low-end web servers, DNS, ftp, etc.

You'll need to decide how you want to virtualize your system -- z/VM or 
LPAR.  LPAR+RHEL is common criteria'd, sponsored by IBM.  I've found it 
easier to train a Linux staff member on z/VM than a z/VM person on Linux 
-- but that's my own perception, talent of your team matters most.  IBM 
has a few training classes out there, but the one's I've seen are mostly 
install-lab type activities (versus detailed storage management, memory 
management, etc).

Read into CMM1 -- it may yield you significant performance boosts.  
http://www.vm.ibm.com/perf/reports/zvm/html/530cmm.htm

For a manual, you'll find the RHEL5 RedBook handy. 
linuxvm.org/Present/misc/virt-cookbook-RH5.pdf

Linuxvm.org is a great resource for presentations, 
http://linuxvm.org/Present/index.html

-Shawn