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
