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dpueltz
28-Mar-2013, 15:01
Hi everybody,

where is the big deal in running Linux on System-z? Hardware-Invests in IFLs and RAM are extremely high (compared to Intel-based ESX's), so that most memory-eating Applicationserver-Workloads seem to be very expensive. Also I cannot see big cost-saving-effects in e.g. Oracle-Licensing - keep in mind that Oracle-Licensing-Factor for intel ist 0.5, for z 1!

Regards, Det

ab
28-Mar-2013, 15:39
Being a SLES lover I saw SLES on System Z for the first time late last
year and was pretty impressed with some of the zSeries tool behind my OS.
Since people go for it I imagine the benefits are there, and many of them
are detailed on the product page:

https://www.suse.com/products/systemz/

Some of the things I remember, insane uptime and redundancy options thanks
to the mainframe hardware fun, use of mainframe virtualization tools that
have been used and made solid over the last (as I recall) forty years,
software license costs when those are based on real hardware (the same
benefits any virtualization solution sees), really quick creation of new
VMs, etc.

In the end the proof is in the market; that customers want it means it is
a better option for them than alternatives (other distros in mainframe, or
other non-mainframe options).

Good luck.

Bob-O-Rama
29-Mar-2013, 04:38
The z-series can be configured with ridiculous MTBF. Even comparatively low end z systems might have MTBF in excess of 30 years. If you have a system which cannot fail, eliminating hardware failures / upgrades eliminates the major source for this risk. Consider an OLTP box where you get a penny a transaction, even 5 minutes of down time can pay for the entire system. Now consider a commissioned trade, where instead of pennies it might be dollars, or tens of dollars. Its a system that makes sense when downtime means death or bankruptcy. Or when you need to get the answers right on Jeopardy!

-- Bob

cjcox
31-Mar-2013, 02:12
On 03/28/2013 09:04 AM, dpueltz wrote:
>
> Hi everybody,
>
> where is the big deal in running Linux on System-z? Hardware-Invests in
> IFLs and RAM are extremely high (compared to Intel-based ESX's), so that
> most memory-eating Applicationserver-Workloads seem to be very
> expensive. Also I cannot see big cost-saving-effects in e.g.
> Oracle-Licensing - keep in mind that Oracle-Licensing-Factor for intel
> ist 0.5, for z 1!
>
> Regards, Det
>
>

Apart from the MTBF, which others have mentioned.... a mainframe runs workloads
more evenly. Thus even if you perceive it to be slow... as the load increases,
the performance doesn't drop that much. So it can be loaded pretty heavily.
The number of Linux guests you can run under zVM is very high (e.g. thousands of
VMs). How much money would you have to invest to run thousands of Linux VMs
using x86 hardware? (and would it be all that reliable... and would it be easier
to run and keep up with, etc.. etc...)

But with that said, a mainframe does mean a commitment... and for some, the
initial cost and even "the promise" it holds, well... it can be daunting...

So.. it still not necessarily the best fit for all worlds. It's not like the
"old" days where a Systems Programmer was a resource you could find
"everywhere". And I'd recommend having somebody that understands zVM.

With regards to mainframe software licensing, which is often times leased.. and
it very expensive, that's something you'll also need to look at.