To be honest last time when I was installing z/OS and other products in
ServerPac, one of the products insisted to use HFS because of size. To
explain: until recently ZFS had to be limited to 4GB or be SMS-managed
and Extended Format (and then EA).
While it would be possible to change it later or just copy HFS content
to new ZFS I simply gave up and left one HFS within a bunch of ZFS
filesystems.
BTW: I liked HFS because HFS need not to be cataloged, which makes
system cloning and servicing simpler. And HFS can be cataloged twice, in
two different systems. Of course there are ways to skin ZFS cat also.
--
Radoslaw Skorupka
(looking for new job)
Lodz, Poland
W dniu 18.05.2021 o 15:19, Charles Mills pisze:
HFS is rapidly disappearing if not gone in most installations
But replaced by zFS, which to the casual end user is pretty much the same
thing: "UNIX files on z/OS."
I didn't want Steve to get the impression that UNIX files had gone away.
+1 to what Timothy says about bytes: particularly if an application can
exploit above the 2GB bar storage, bytes have quit being something to worry
about. Heck, the above-the-bar "GETMAIN" functions only work in increments
of a megabyte -- you can't allocate 10K or 100K. Everyone still worries very
much about CPU cycles, so if you can trade a couple of megabytes of storage
allocated for a couple of seconds of CPU time saved it is well worth it.
Charles
-----Original Message-----
From: IBM Mainframe Discussion List [mailto:[email protected]] On
Behalf Of Timothy Sipples
Sent: Tuesday, May 18, 2021 6:10 AM
To: [email protected]
Subject: Re: Best catch up resources for MVS / ZOS Technologies
A bit more from me....
The IBM Learning System is also available if you'd like to go grab a free
z/OS account to "kick some tires" (and with no service level commitment).
The 2020-2021 "Master the Mainframe" contest has ended in terms of prizes
and awards, but you can still try the contest exercises and earn "digital
badges."
https://www.ibm.com/it-infrastructure/z/education/master-the-mainframe
Some of exercises cover Python, Ansible, and Zowe, as examples. Ansible
was born in 2012, Zowe in 2018. Python technically began in 1991, but it
took a fairly long time to mature and get popular. There's a Slack channel
where you can ask questions about the IBM Learning System and the various
exercises.
If recent past history is a guide (no guarantees) the IBM Learning System
will probably go offline sometime in August, 2021, and then pop up again,
refreshed, sometime in September, 2021, for the 2021-2022 contest. The
2021-2022 contest will have a new name.
There are at least a few technologies you can probably safely "erase from
your memory banks," or at least reduce allocations for. As David alluded
to, SNA protocols, and even (perhaps, notionally) some pre-SNA protocols,
are still supported. However, in typical operational practice, you can
function quite well knowing at least a great deal less about these network
protocols. Nowadays Enterprise Extender knowledge is plenty, if you even
need that, since EE is where SNA is rapidly converging -- or already has,
really. All the AnyNet variants are gone. There are some ancient access
methods that are now only historical, and HFS is rapidly disappearing if
not gone in most installations. There's no more ESA/390 (or prior) IPL, no
Basic Mode (only LPARs of various types), no Sysplex timer boxes (they're
now onboard as Server Time Protocol), and even the physical Hardware
Management Console (HMC) can now be a virtual/integrated one on the IBM
z15/LinuxONE III models. Work is well underway to make the HCD/IOCDS stuff
much simpler, chiefly via Dynamic Partition Manager. Parallel (bus/tag)
and ESCON channels have disappeared, although if you really need to
connect an old device you still can courtesy Optica's equipment. Copper
Ethernet is all full duplex 1000BASE-T now, with no more 10 or 100 -- and
nothing to configure in that respect. No more Token-Ring or coax either.
You don't need to worry about classic Microsoft Windows-style CIFS/SMB
network file sharing or TCPBEUI since that's all been retired in favor of
NFS. We're way past all the "bimodal accommodation" stuff for 64-bit
toleration, and you haven't even been able to run z/OS in anything other
than z/Architecture (64-bit) mode since z/OS 1.6 (released in 2004). The
BookManager family of products has (sadly perhaps) receded, but you can
still open and read a .BOO document on a PC if you need to.
Related to those huge memory sizes, you can forget about treating every
byte as precious; they aren't any more, not that much. System memory is
quite inexpensive now, and if you can buy nontrivially greater processing
efficiency using more memory you should take that deal every time. But 20+
years of favorable economic evolution and performance tuning have changed
CPU thinking, too (or should have). For example, today's Db2 on average is
a heck of a lot more processor efficient than 2001's DB2, which is pretty
remarkable really. COBOL, too (Enterprise COBOL 6.3), as another notable
example.
OpenSSH is quite important on z/OS, and that's new compared to 2001. In
2001 parsing and generating XML was important, but now JSON is much more
important while XML is still supported. z/OS supported Unicode even back
in 2001, but z/OS is typically storing and managing much more Unicode data
in 2021 -- and doing it much better. EBCDIC codepages are still supported,
of course. There's something called Metal C that can be a great
alternative to Assembler, if you wish. Naturally HLASM is still supported
and keeps evolving.
On balance there are many more (and more interesting) "freebies" available
for z/OS. The 2020 edition of my list is available here:
https://community.ibm.com/community/user/ibmz-and-linuxone/blogs/timothy-sip
ples1/2020/10/15/mainframe-freebies
Welcome back! :-)
- - - - - - - - - -
Timothy Sipples
I.T. Architect Executive
Digital Asset & Other Industry Solutions
IBM Z & LinuxONE
- - - - - - - - - -
E-Mail: [email protected]
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