Charles Mills wrote:
>- Everything is of course bigger. Z hardware goes up to
>what? 4TB real? Someone will correct me if that is wrong.
The IBM z15 T01 and LinuxONE III LT1 models can have up to 40TB of real,
customer usable memory per machine. Each LPAR can have up to 16TB, and
each z/OS instance supports up to 4TB, plus any Virtual Flash Memory
(VFM).
>- Tape drives have pretty much gone away. They live on
>as virtual, emulated-on-DASD tape drives.
No, not actually. There's more physical tape storage out there in the
world than ever. "Small" mainframe installations often don't have physical
tape drives, but "large" organizations often have a lot -- and cloud
storage providers use *incredible* amounts of physical tape. The
media/entertainment and scientific communities are also driving huge
demand for physical tape.
It's possible and relatively common to emulate tape drives on "DASD" (i.e.
FICON-attached ECKD storage). That's *one of* the functions IBM Cloud Tape
Connector for z/OS provides, for example -- and you may or may not use
that function (formerly called Virtual Tape Facility, or VTF for short).
However, the physical virtual (!) tape products such as the IBM TS7700 use
their own dedicated storage that you don't really "see" that's not
addressable as 3390-style volumes.
Anyway, your general point is absolutely spot on, that essentially "all
tape, disk, and flash storage is virtual in practice." Even when you have
physical tape drives and cartridges on premises.
IBM introduced the industry's first encrypting tape drive, the IBM TS1120,
in 2005 (after Steve's 2001 cutoff year). It would be surprising or even
shocking if you're not encrypting *at least* physical tape cartridges in
2021.
>- The Cloud. Read any airline magazine for the latest.
And z/OS plays very well in/with "the Cloud." Some examples:
* z/OS Cloud Broker
* Cloud Tape Connector for z/OS
* Z Development & Test Environment
* "API economies" (z/OS Connect)
* data privacy protection (Hyper Protect Data Controller)
* z/OS Container Extensions
....With even more coming, and that's not a secret. "Watch this space."
>- Speaking of which, there is a Z box that will not
>IPL z/OS! It is called Linux One. It's a mainframe
>with a bit hobbled somewhere such that mainframe operating
>systems will not IPL, only Linux.
First of all, historically there have "nearly always" been mainframes that
could not run z/OS (or its predecessors). They typically ran z/VSE (or its
predecessors) and/or z/VM (or its predecessors).
IBM announced IFLs on August 1, 2000, and they were available starting
with IBM G5-based machines. That date beats Steve's 2001 cutoff. The IBM
LinuxONE servers are exclusively (or almost exclusively anyway -- there's
one quirky exception) equipped with IFLs, as IBM Z machines can be if you
wish. They're not "hobbled" at all. If you wish, you can convert an IBM
LinuxONE machine to an IBM Z machine. As I write this the Z model
conversions are available for IBM LinuxONE II and LinuxONE III machines,
although IBM has announced 2022 End of Marketing dates for IBM LinuxONE II
to IBM z14 conversions. As it happens, there are a couple I/O features
that are only available for IBM LinuxONE machines that are not available
for IBM Z machines. Does that mean IBM Z machines are I/O "hobbled"? No,
not really. The model families just have different feature sets.
IBM LinuxONE machines also run z/VM, an operating system in its own right.
All z/VM features and functions are available and authorized/licensed for
all Linux-oriented use cases.
Later this month (May, 2021) IBM will start fulfilling customer orders for
IBM LinuxONE III Express servers. In some countries, starting in the U.S.,
you'll be able to order one (or more) of these servers online with a few
clicks or taps.
>JCL has not gotten any better (or any worse, thankfully).
It's gotten better in some notable respects, e.g. NOTIFY, long parameter
lists (>100 characters), and SCHEDULE. There's also a lot more automatic
generation and submission of JCL via (one example) the z/OS Management
Facility. The first release of z/OSMF debuted in 2009 with z/OS 1.11 (and
was backported to z/OS 1.10).
>- IBM JES3 is dead. Long live Phoenix JES3 plus. IBM ditched JES3,
>and Phoenix picked it up.
More accurately, the forthcoming (2021's) z/OS 2.5 release is the last
z/OS release to offer IBM JES3 (an option). IBM JES3 will be supported on
z/OS 2.5 as long as z/OS 2.5 is IBM supported (i.e. a long time). IBM
generally recommends migrating from JES3 to JES2 and has enhanced JES2 and
z/OS in various ways to make the migration easier, but Phoenix's JES3 plus
is a possible choice.
>- More emphasis on high level languages. Hardware design is
>being driven by the Java folks and the compiler folks. Lots
>of new hardware instructions.
Additional popular programming languages on z/OS include Python, Go
(Golang), and JavaScript (Node.js).
>Anyone else want to weigh in?
There are obviously many more developments over the past 20 years. Another
big one that comes to mind is that, in 2001, even IBM advised against
using IBM Z ("zSeries" back then) and z/OS much or at all for data
warehousing, business intelligence, analytics, and machine learning.
(Sometimes I was the one giving this advice -- and encouraging development
of better options by 2005, as I recall.) What you were *supposed* to do
back then is Extract, Transform, and Load (ETL, or ELT) data from your
z/OS-based System of Record over to an external data warehouse (usually
DB2 on AIX, Teradata, Oracle, Informix, or Sybase), perhaps feed some data
marts too, and run whatever analytics you wanted to run against all that
necessarily stale, unprotected data. Not any more! IBM Z, z/OS, and their
accelerators are now exceptionally good at handling transactional,
analytical, AND batch data access patterns concurrently. Nowadays we focus
a lot on "data gravity," bringing analytics and AI to the data rather than
the other way around. Nobody is able to solve whole classes of problems
any other way -- physics (speed of light/electrons) won't allow it. These
workloads are much, much more important now than they were two decades
ago. There are many use cases -- notably Hybrid Transactional Analytical
Processing (HTAP) use cases involving real-time scoring and instant
risk-based decisions -- that work best (or work at all) via "onboard"
analytics. Yes, there are still many organizations that haven't caught up
with these modern realities, but here they are, and they're amazing. The
IBM Db2 Analytics Accelerator, Open Data Analytics for z/OS, and Watson
Machine Learning for z/OS are notable examples in this broad category.
After 2001 IBM introduced a new specialty processor, the zIIP, exclusively
for z/OS's benefit. zIIP's progenitor, named zAAP, was introduced in 2004,
so this all happened after 2001. zIIPs are easy to understand and use, I
think, which is probably why you didn't specifically mention them.
Parallel Sysplex and GDPS have evolved a great deal, in all directions.
I'm a big fan of single machine Parallel Sysplexes if you don't already
have a Parallel Sysplex since the value-for-money equation is typically
phenomenal. GDPS now includes sophisticated "Active Sites" variants that,
in simple terms, support continuous service, with transactional integrity
and consistency, even if/when a whole site if offline.
Steve probably "missed" the 4 hour rolling average (4HRA) since Variable
Workload License Charges (VWLC) were very new in 2001. Various WLC
arrangements are still available and common, but IBM also now offers
Tailored Fit Pricing (TFP) with no monthly 4HRA peaks to worry about. On
Off Capacity On Demand (OOCoD) and System Recovery Boost are probably new
to Steve. It's also possible and common to get differently (much lower)
priced development and test z/OS environments, even for stress testing,
and to get out of the way and let developers self-provision them --
"disposable z/OS" instances. If a developer damages or destroys a whole
z/OS instance, no problem, the developer throws it away and brings up a
new one from the standard build catalog. Speaking of which, z/OS supports
Git and gobs of other "DevOps" tools.
Steve probably missed z/OS Workload Manager's (WLM's) goal mode, so there
might be an important WLM concept to learn and enjoy. There are some very
nice LPAR-related innovations, too, such as LPAR group "softcaps."
Application Performance Management (APM), Data Access
Management/Governance (DAM), Identity and Access Management (IAM), network
security, and Security Incident and Event Management (SIEM) -- and their
various intersections and partnerships with z/OS -- have changed a lot
since 2001. A couple of those categories barely existed in 2001, or at
least they had different names.
Encryption key management is quite important, as you allude to. Back in
2001 you could perhaps "wing it" when it came to understanding and
handling SSL certificates, for example. You ought to become more
comfortable with cryptography if you aren't already, to get familiar with
more of the basics. Similarly, you might have been able to "wing it" in
terms of understanding the basics of z/OS UNIX System Services. Now (and
for some time) you simply cannot avoid z/OS UNIX if you're a z/OS operator
or administrator. In fairness, you cannot avoid the basic concepts (such
as zFS's /this/is/a/directory...) really anywhere since practically all
operating systems have adopted Linux/UNIX conventions. Even Microsoft
Windows, belatedly.
It's much more likely now that you'll be expected to perform various
upgrades, including whole machine model generation upgrades, without
application outages. Even in 2001 business expectations had started to
shift, but now they've *really* changed. Fortunately the IBM Z platform
and z/OS software products support all sorts of nondisruptive upgrades and
changes when suitably configured and reasonably competently operated. (And
if IBM has missed something, please let IBM know.)
Internal networking, within the IBM Z server, is hugely different (better)
now, lately with SMC-D.
Printer output paths are quite different in 2021. Most organizations have
cut way back on their bulk printing, with most or all of the former paper
output redirected into electronic forms, often encrypted. There are
various z/OS software products that process and manage output such as bank
statements, including IBM's products. z/OS can still print to paper, of
course, and via various network protocols and printer data streams.
- - - - - - - - - -
Timothy Sipples
I.T. Architect Executive
Digital Asset & Other Industry Solutions
IBM Z & LinuxONE
- - - - - - - - - -
E-Mail: sipp...@sg.ibm.com
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