Exactly, but the issue is to explain this to peter principal IT managers.
Paul Raulerson wrote:
I am very confused indeed by this whole conversation -VMWARE and z/VM
solve different solutions. And they are both extraordinarily good at
what they do.
Just at the 10,000 foot level, VMWARE is designed to virtualize PC
hardware and z/VM virtualizes mainframe hardware. Dismissing this as
just "two different hardware platforms" is rather disingenuous, though
admittedly, it is a "true" statement. Then again, a nuclear powered
aircraft carrier and diesel powered megaton oil tanker are both ships
- just "two different hardware platforms." They hardly operate in the
same realms though.
Where everything starts to get different is the underlying hardware.
And at that level, it gets very VERY different indeed.
In some ways, VMWARE is more like an LPAR than a VM guest instance, but
that difference is driven more by the hardware capabilities than by the
design.
-Paul
On Nov 1, 2008, at 6:34 PM, Barton Robinson wrote:
One thing that really bothers me about VMWARE. When I ask about
performance to the people that measure, they tell me the VMWARE
contract specifically states they are not allowed to talk about it's
performance. A vendor that won't let people talk about performance
must be very afraid details will be made public and don't really need
to invest in improving it's performance. Since we can not provide
facts to confuse management, it comes down to religion or companies
providing their own facts.
A professor from I think Stutgaart presented last year at the GSE/ IBM
meeting pretty convincingly that VMWARE was about 20 years behind
z/VM in almost any "fair" technological aspect you wish to evaluate.
And I think he was wrong - I don't see sharing of resources in VMWARE
even what z/VM had 20 years ago. VMWARE is much more like LPAR, so
any argument you can use for z/VM vs LPAR works as well.
I believe VMWARE is great for desktops where users may want to run
applications that only run on different versions of windows or
Linux. Now there is a company in California that is even
virtualizing the desktops, give end users a small appliance, keyboard
and monitor, and the software runs on a "virtualized PC", where all
software runs on the central "virtualized PC" that then supports
multiple users. They save a lot of money by only having one copy of
MS Office to support multiple end users. (Does this sound like 3270
and mainframes to anyone else?)
Alan Ackerman wrote:
Another question from the same architecture person. What is the
value add
ed by z/VM over VMWARE for a Linux workload? (That's my wording, not
his.)
As usual, I don't know anything about what VMWARE can or cannot do.
I'm s
ure it can run fewer guests than VM, but not how many. VM has shared
DASD and DCSSes and NSSes
, but most Linux people don't see the value of those things -- disks
are cheap and come wi
th the PC, memory is cheap, etc. VM has automation capabilities, but
Linux has those too, and IBM sells all those Tivoli products to tie
them together, report performance, provide high availabil
ity, etc. I think the advantage on the mainframe is economy of
scale. But how do yo
u measure that?
At present, you can save money on software and peripherals enough to
cost
-justify the mainframe. Reduced people costs are hard to quantify
and scare the heck o
ut of the midrange folks.
But I wonder how long those software prices will last? Red Hat
charges $1
8,000 per IFL for 7x24 support. (I found that on a web site, and I
asked our Red Hat representat
ive to make sure.) I couldn't find any prices on Novel SuSEs web
site. We have other software with higher prices per engine for the
mainframe. He specifically mentioned the ability to pick up a Linux
guest running un
der VMWARE and moving it to another box running VMWARE. So far VM
cannot do that. Ideas on what value z/VM adds would be appreciated!
Alan Ackerman
Alan (dot) Ackerman (at) Bank of America (dot) com
