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Copyright 2001, 2002 Robert H. (Bob) Johnson. Permission is granted to attendees to make copies of this material for their publications and for attendees’ one-time usage. All other rights reserved.
Copyrights MVS Concepts and Facilities (ISBN 0-07-032673-8, Spanish translation = 84-481-092-1, McGraw-Hill Madrid) is copyright 1989 Robert H. Johnson Jr. DASD IBM's Direct Access Storage Devices (ISBN 0-07-032674-6 copyright 1992 Robert H & R. Daniel Johnson). UNIX as a Second Language (ISBN 0-9650929-1-7) is copyrighted 1995, 2001 by Robert H. Johnson . All other products and brand names mentioned are trademarks or registered trademarks of their respective holders. Contents may settle during shipment. Your mileage may vary. Warning, contents under pressure.
The information contained in this presentation is distributed on an “as-is” basis without any warranty either express or implied. The use of this information or the implementation of any of these techniques is the reader's responsibility. Neither the authors nor this conference is responsible in any way for the reader's application of this information.
Disclaimer-2 This presentation is designed to start a dialogue within the industry on the future of UNIX in mainframe computing. This area is one of the most important arenas for the 21st century. In order for us to be successful, we need understanding and discussion on the topic. I share what I know and discover. I challenge you to do the same.
CMG 2000 wanted a panel on IBM’s support of Linux on z/900 platforms and what that meant.
I “volunteered” to chair the panel.
The experts took over from there!
Over the rest of 2001, I filled in the pieces with my own research.
How is Linux different from USS? What performance and capacity metrics are available (or planned?)? What workloads run on S/390 Linux? In terms of eCommerce, which UNIX system is "better" for WebServer- USS or Linux?
Disclaimer The basis of this presentation was a summary of a panel on the topic at CMG/2000 in Orlando Florida, USA, December, 2000, AND my extensions of these findings. If there are errors or omissions, then the problems are mine. If there is good stuff, then it must have been provided by the panelists: Peter Enrico, email@example.com www.epstrategies.com Mark Cathcart, IBM http://www.ibm.com/s390/corner; Ross Patterson, Computer Associates <ROSS.PATTERSON@ca.com>, or Tim Kane, firstname.lastname@example.org
0001 - Rebranding of families: z/Business and e/Server
0010 - Why UNIX on S/390 and z/900
0011 - Will the real UNIX stand up
0100 - Linux? What Linux?
0101 - Unix Systems Services
0110 - Which UNIX to Pick
0111 - Should You Run Linux on VM or VIF?
1000 - Application Considerations
0001 Re-Branding of CPU families
Supercedes RS/6000 and Sequent NUMA-Q
Linux available for full suite of eServer machines
“Freeway” - The z900 Series
64-bit zArchitecture with z/OS
Built on new copper technology
Up to 64GB of memory
“above the line”
“above the bar”
Aggregate I/O bandwidth up to 24Gb/sec -- that’s GIGABYTE!
z/OS Intelligent Resource Director (IRD): Linux enabler?
“Freeway” - 2
Up to 640 processors in a Parallel Sysplex
20 x 32 (up to 16 Central Processors, 3 System Assist Processors, and 1 spare CP)
20%-30% faster than G6
“not even close to maximizing out Moore’s Law”
“Freeway” - 3
Intelligent Resource Director (IRD)
Manages LPAR cluster (within a single CEC)
Stripped down WLM: assigned workload goals
Moves resources TO and FROM workloads not workloads to and from resources
IRD requires WLM in each LPAR and z/OS
HiperSockets and Linux Support
Virtual TCP/IP network within a CEC
Freeway - 4
New IBM Pricing Options - Linux for S/390: XSLM
Workload License Charge
IBM and ISV must build license installation, policy and system installation, reporting, logs, and contract management
Requires z/OS in 64-bit mode on z/Series server
Freeway - 5 Linux World in New York, February 1, 2001: VM's and Linux/390's own Jim Elliott walked up to the podium at the VIP reception to accept an award on IBM's behalf. It seems the IBM zSeries model z900 won the "Best Hardware" category - not bad for a dead dinosaur platform, eh?
0010 Why UNIX on S/390, z900, z/VM, VIF, and z/OS
“z” is for “zero downtime”
“Reliability, Availability, Serviceability (RAS)” was invented here
Why UNIX on S/390 z900 - 2
“SUN UE10000 (Sun Cap) is about where 3084 was in 1984 for RAS”
“Major online systems suffer 11 hours downtime due to back-end storage failure.”
Application development on a widely available, volume platform.
Use of the volume platform for initial deployment with minimal barriers, and
Minimal barriers for scale from low to high (IBM S/390 Bulletin 28, August 2000, page 16-18)
0011 Will the Real Unix Stand Up
UNIX is really hundreds of variants
UNIX 95/98, etc is a collection of subsystem calls that must be honored to be “UNIX” all of them have these
SUN (SOLARIS), IBM (AIX), HP (HP/UX) have these and lots more but cost money
Linux has all of them, but is “free”
0100 Linux? What Linux?
This is the real Linux -- the one written by Linus Torvalds. “Bigfoot”
Same as the one you download from Redbrick.com
gnu toolkit was used to write microcode for s/390
“ less than 1% of Linux is modified”
Linux meets IBM’s objective of selling RAS hardware for UNIX: z/900
Linux is just like what you can download to your PC -- a real primitive operating system.
Linux on z/900 gives IBM customer true choice.
S/390 Linux Benefits
Based on z/Architecture which allows unlimited addressing
zSeries servers automatically direct resources to priority work through Intelligent Resource Director (IRD)
Parallel Sysplex clustering technology
Numerous operating systems images managed as a single dynamic workload
dynamic CPU weight (only--Linux does not have a “vary CPU offline”, no dynamic channel paths, channel control paths
HiperSockets (four, VM allows sharing) let TCP/IP traffic travel between partitions at memory speed (Gigabyte) rather than network speed: one gigabit per second per pipe (of 24)
Virtual Internet Protocol Addressing (VIPA) provides transparent failover from device, interface or network failures
Channel Subsystem Priority Queuing and Dynamic Channel Path Management are part of normal S/390 or z/900 implementation.
Naspa Article: November 2000; Page 24: Adam Thornton on David Boyes
Two G5 Class S/390 Processors
EMC disk unit
250 to 10,000 users
41,400 servers: did not crash, just ran out of VM resources
VM design goals: 100,000 simultaneous virtual machines
Update: almost reached 100,000 servers!
0101 USS: Introduction
Integral part of OS/390 since 1994
Known by Different names:
USS: Integral to Operating System
Unix Systems Services (USS) is an integral part of the OS/390 operating system and provides UNIX services to OS/390 applications and users
USS provides access to either UNIX files or regular “MVS” files or both from the same program.
USS: Always There
USS will always be a part of z/OS
USS will continue to be used for primary z/OS components that need USS:
TCP/IP, Websphere Commerce Suite, Domino, Webserver, Java, etc.
Most improvements of USS by IBM will most likely be targeted for these products/components
View of USS Interface
What’s Running on USS?
Lotus Domino- Go Server & Lotus Notes
ERP programs- Baan, SAP
0110 Which Unix to Pick to run application code
Data centers already have USS running when they bring up OS/390 or z/OS 1.1. Everybody has USS.
If data centers want to run Linux, they must plan for, and dedicate resources to Linux.
If you need ANSI Standard C++ with standard template libraries (STL)
If you want all of the gnu tools and anything else you can get downloaded and fixed up on your own
You want porting speed and cost: You must recompile your application. It is an ASCII environment after all.
Pick Linux - 2
You want complete ASCII support including multiple byte character set (MBCS). (i.e., If you are in or like Pacific rim companies who will be early adopters -- 64-bit is ideal for languages such as kanji).
You want horizontal scalability
Pick Linux -3
Key middleware deployment
WebSphere Application Server - Advanced Edition
Java connectors to - DB2, IMS, CICS, MQSeries
DB2 UDB, workstation DB2, not Sysplex capable, IBM DB2 connect???
MYSAP.com: application on UNIX; DB2 on z/OS; HiperSockets
VM/ESA or IBM S/390 Virtual Image Facility for Linux
S/390 G6 and Shark to run 1,500 virtual Linux servers for customer web sites
Displaces 70 Sun servers
Telia is able to set up a Linux for zSeries server in less than 5 minutes as opposed to 5 hours with Sun
“ Converting from G5 to z/900
Ringing Bells at Telia.Net Linux for S/390 images Single purpose Internet-related servers Server farms Consolidation e-business
Recreational Vehicle Manufacturer
Replaced Microsoft Mail and Novell servers with Bynari Insight Server
Users can still use Microsoft Outlook e-mail client
New function and services OS/390 inter partition communication OS/390 Consolidation
"The new IBM S/390 system runs LINUX for S/390 giving the capability for hundreds of Linux images for student and academic use. S/390 will run the Open Source Linux Operating System under the IBM VM/ESA Operating System. The provision of Linux for S/390 is one of the most significant developments in the fast-growing use of the Linux operating system."
University Press Release Jan 2001 University of Warwick ..also in Dublin City University
Start-up online game server company
Provides services for virtual "Dream Soccer" games
Scaling to 15,000 concurrent Soccer game by year-end 2001
IBM ^ z900
15 partitions of Linux: for games, relays, web servers, and date updates
Optimise the network by adopting a mainframe-class engine server
Highest average resource utilization 70% vs 15% (13%)
100x Mean time between failure (“37 years”)
1/4 network equipment costs.
Pick USS - Quality of Service - 2
Websphere and Java
Pick USS - for Application Software
Tape and offline storage
Pick USS - Operations
USS has access to SMF (OEM software gives full accounting possibilities
Linux gives minimal possibilities via IOSTAT, VMSTAT, and SAR commands and write-your-own and OEM programs.
Pick USS - Device Connectivity
USS has all of OS/390 and z/OS connectivity. Linux must have drivers “written” for them
DASD: CKD and FBA is fine
TAPE: all fine with USS; Linux is under development
PRINT: JES wins; although Samba print solutions for Windows-style printing under Linux.
Pick USS for Human Resource reasons
A young person can be “taught” mainframe if it is “UNIX”
0111 Should You Run Linux on VM or VIF?
Linux runs on
metal (dedicated machines)
VIF (hidden machines)
as a Virtual Machine under VM
Even under MVS (SHARE presentation at SHARE 95, session 5511)
VIF is subset of VM
VIF machines are all peers
no controls over which Linux system has control
no system backups
no systems monitors
Requires dedicated CPUs--no sharing
VIF - 2
very easy to clone machines (no systems programmer required)
Runs in Integrated Control Facility (ICF)
Runs on “hidden CPU’s” and is charged for usage only -- the CPUs are not part of other software billings.
How long will this continue? Gone.
Requires VM systems programmer resource -- very valuable
Much more flexible
“ must fix 100 hz timer pop” else 5-6% of G5 or G6
96,000 under test load (David Boyes latest “plan c”
VM: Sine Nome Associates
Dr. David Boyes
Task: for phone company: build customer server
Old way: 3 machines each customer; 18.7 miles of Ethernet; $65 million; 7 days
Linux on mainframe: 30 minutes; 10%
1000 Application Conversion Considerations
Linux may be much faster to port applications (maybe just a compile) -- weeks to days
Linux will be much quicker to get to 64-bit addressibility (immediately) vs 2002 (?) for USS
Run NT applications on Linux
WinStar programs run under Linux and almost emulate Windows environments?
1001 Monitoring UNIX on the Mainframe
UNIX on the mainframe will need monitors that understand things not seen by standard monitoring techniques. There are ASIDs and Tasks, but you will need to see processes, threads, HFS, etc.
BMC: “ Linux for S/390 Management”
5 Feb 2002: Patrol agent, Control M (scheduling)
“ Patrol agent and Linux Knowledge module” (KM on the Linux for S/390 platform
It requires Mainview
The problem is that Patrol can only gather information that Linux provides and that is very little.
IOSTAT, VMSTAT, etc: lots of freeware
3 Levels of USS Pain
Not running any applications
May be unfamiliar with USS and resources it is consuming- In the dark
Future plans to install applications
Discomfort becoming real - Dawn
Currently running applications
Performance at risk- Wake up!
1010 Q&A CMG has a tradition of holding “Birds-of-a-feather (BOF)” sessions at the end of the day where attendees can discuss current topics in an ad hoc manner. Since I expected some discussion to continue, I scheduled a BOF session. Sure enough, 40 people showed up! Six installations had Linux running (maybe some were duplicates) The following were questions (and answers) as noted. Many of the comments were worked into the notes above.
Q & A
What about Shared DASD under Linux?
There we go again. -- probably not in near future.
Linux needs to have device drivers written for it. It may never have shared DASD unless it is implemented by Storage Area Network (SAN) architecture .
How in the dark are you?
Do you have a good understanding of what’s going on in your USS/Open Edition environment?
What applications are you running on USS/Open Edition?
How in the dark are you?
Have you been seeing more and more USS activities showing up on your MVS monitor?
Do you know if USS is using 5, 10 or 50% of your MVS resources?
Can you tell which tasks are using, or maybe abusing, your USS resources?
How are you with UNIX?
Are you comfortable with USS file structures and Unix commands?
How critical to your business will the applications running on USS be?
How did the installation of the USS application you are running go?
Have you had any jobs get hung up that you needed to kill?
Do you think that your thresholds are set properly at this point?
Unix as a Second Language (Bob Johnson - self published)
“ Linux on S/390 or z/Series: Getting Started” Lionel B. Dyck; NASPA September 2001 pp36-41
Linux Security: Session 1745, SHARE 97, July 26, 2001, Minn, MN Mike Kearney, Washington Systems Center,
The Linux/390 list:
The Linux/390 Community website:
IBM’s Linux/390 website: “Free z”
WWW.IBM.Com/ servers /eserver/zseries/os/linux/
get yourself a free Lunux machine!
Jim Elliott: www.vm.ibm.com/devpages/jelliott/linux.html