> - Tape drives have pretty much gone away. They live on as virtual, > emulated-on-DASD tape drives.
Remote copy is fine for, e.g., hot backups, but when you need to retain old versions of your data back a long stretch of time, tape is still an inexpensive solution. I suspect that there will eventually be a solid state storage medium with the cost per byte of tape, but we aren't there yet. -- Shmuel (Seymour J.) Metz http://mason.gmu.edu/~smetz3 ________________________________________ From: IBM Mainframe Discussion List [IBM-MAIN@LISTSERV.UA.EDU] on behalf of Charles Mills [charl...@mcn.org] Sent: Monday, May 17, 2021 11:45 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Best catch up resources for MVS / ZOS Technologies Steve, let me wade in here and suggest some big picture. I think SHARE and such is great for the details. What has changed since 2001? An idiosyncratic, IMHO list: - In 2001 SNA was yielding to TCP/IP. That transition has continued. An awful lot of mainframe connectivity is now TCP/IP. Lots and lots of Internet connectivity to the mainframe. - Security is huge. Encryption is hot. Zero Trust is the buzzword of the month. - Everything is of course bigger. Z hardware goes up to what? 4TB real? Someone will correct me if that is wrong. - Tape drives have pretty much gone away. They live on as virtual, emulated-on-DASD tape drives. - The Cloud. Read any airline magazine for the latest. - Remember VM? It was pretty moribund in 2001. It has found new life hosting thousands of Linux instances. Yes, Linux running like a champ on Z hardware. Mainframe Linux is huge. You can run Linux in a region of MVS in a "container." - 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. - Lots of new features in core MVS but you would fully recognize the environment. If you sit down at a TSO/ISPF session it will seem like nothing has changed. JCL has not gotten any better (or any worse, thankfully). - Remember the issue of "above the (24-bit) line"? It is still there, but pretty much in the background. The new thing is data and execution "above the (2GB/31-bit) bar." Lots of software products are exploiting data above 2GB, and code can even run there, with lots of limitations. AMODE/RMODE 64. - IBM JES3 is dead. Long live Phoenix JES3 plus. IBM ditched JES3, and Phoenix picked it up. - More emphasis on high level languages. Hardware design is being driven by the Java folks and the compiler folks. Lots of new hardware instructions. Hardware cycle times are not getting any faster, but instructions do more per cycle. Caching getting more sophisticated and more critical. The concept of "how long does an LR take" has totally disappeared. It is a question with no answer other than "it depends." Anyone else want to weigh in? Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:IBM-MAIN@LISTSERV.UA.EDU] On Behalf Of Gibney, Dave Sent: Monday, May 17, 2021 6:58 PM To: IBM-MAIN@LISTSERV.UA.EDU Subject: Re: Best catch up resources for MVS / ZOS Technologies I would suggest SHARE presentations and perhaps Marna Walle's migration guides > -----Original Message----- > From: IBM Mainframe Discussion List <IBM-MAIN@LISTSERV.UA.EDU> On > Behalf Of Steve Estle > Sent: Monday, May 17, 2021 6:42 PM > To: IBM-MAIN@LISTSERV.UA.EDU > Subject: Best catch up resources for MVS / ZOS Technologies > > Hello Everyone in Mainframe Land, > > I've been out of the mainframe world since about 2001, but spent the prior > 20 years immersed in that world working with everything from MVS/370 to > MVS/ESA and VM, performance and capacity planning disciplines across a > variety of situations in the IT Services and consulting spaces. I, am, now > as a > "IT Infrastructure Engineer- IBM z/OS Mainframe Engineer" after nearly 20 > years of other activities (Project Mgmt, entrepreneur, etc) am about to > potentially come back into a new mainframe role and I need to catch up as > quickly as possible. Any suggestions on ways to fill in the gaps for ZOS, > ZVM, > hardware, performance, etc? Bottom line I'm looking for that gap education > to as quickly as possible get up to speed with changes in platforms since > 2001. > If prefer to call - all my info is below. > > Thanks, > Steve Estle > 303-604-0925 > sest...@gmail.com > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
