The writer made the comment that :
<snip>
Well, IBM (NYSE: IBM - news) mainframes as old as the original System 370, which
debuted in 1970, had
the ability to create what are called virtual machines, which allow one
version of the operating system to keep running while a kind of duplicate
copy running on the same physical machine is upgraded. Once a fix is made
to code, the patched version of the OS can be swapped into place for the
running version, all without taking down the system.
</snip>
Further . . .
"Once a fix is made to the code, the patched version of the OS can be
swapped into place . . . without taking down the system"
I've been a sys.prog. for about 20 years, 15 of those in VM and I don't
know of any feature that will let a sys prog do this! If so, I've spent a
lot of late nights and weekends upgradeing when I could have done it
during the week. In reality, no you do not have to power the box off, but
you do have to cycle VM or VSE. I'm not sure about z/OS, but since the
author mentions "virtual machines" aka VM, in my opinion he is wrong. Now
don't misunderstand me, I'm for VM getting all the "accurate" press it can
get. However, if some unknowing decision maker takes this and runs with
it, VM could be set up for some bad press. As I understand the article,
he is trying to imply that VM never has to be taken down, cycled, IPL'd,
booted, what ever term you want to use, to bring new OS code in. I should
mentioned one exception that I know of. VSE had/has a mechanism to bring
patched code in. I don't remember the exact process anymore, but it was
used in emergency situations only. I would never apply a list of PTF's to
VSE and bring it on line via this method. VM may have a similar function.
If so I've never used it. Heck, VM hardly ever breaks. (my plug for VM).
But in this case, the method of bring in patched code is not unique to VM.
Sort of off thread. At one site I worked at, me and another sys.prog
convinced the Op. Manager that we had done a "Shadow IPL", i.e, bring new
OS code, more than one module, into use while the machine was still
running. He believed us for about 5 minutes.
Steve G
Phil Payne <[EMAIL PROTECTED]>
Sent by: Linux on 390 Port <[EMAIL PROTECTED]>
03/17/2003 03:45 PM
Please respond to Linux on 390 Port
To: [EMAIL PROTECTED]
cc:
Subject: Interesting perspective
http://story.news.yahoo.com/news?tmpl=story2&cid=75&ncid=738&e=9&u=/nf/20030317/tc_nf/21020
--
Phil Payne
http://www.isham-research.com
+44 7785 302 803
+49 173 6242039
