A Look into Linux on System z with DB2 · PDF fileA Look into Linux on System z with DB2 LUW This presentation is intended to give the audience a look into the architecture of running

© 2011 IBM Corporation

A Look into Linux on System z with DB2 LUW

This presentation is intended to give the audience a look into the architecture of running Linux on System z. The presentation will cover an overview of z/VM capabilities to run Linux as a guest, as well as, helpful tips and techniques while running DB2 LUW in this environment.

Jan Koblenzer Data Management Technical Specialist [email protected]

© 2011 IBM Corporation2


Trademarks

Notes: Performance is in Internal Throughput Rate (ITR) ratio based on measurements and projections using standard IBM benchmarks in a controlled environment. The actual throughput that any user will experience will vary depending upon considerations such as the amount of multiprogramming in the user's job stream, the I/O configuration, the storage configuration, and the workload processed. Therefore, no assurance can be given that an individual user will achieve throughput improvements equivalent to the performance ratios stated here. IBM hardware products are manufactured from new parts, or new and serviceable used parts. Regardless, our warranty terms apply.All customer examples cited or described in this presentation are presented as illustrations of the manner in which some customers have used IBM products and the results they may have achieved. Actual environmental costs and performance characteristics will vary depending on individual customer configurations and conditions.This publication was produced in the United States. IBM may not offer the products, services or features discussed in this document in other countries, and the information may be subject to change without notice. Consult your local IBM business contact for information on the product or services available in your area.All statements regarding IBM's future direction and intent are subject to change or withdrawal without notice, and represent goals and objectives only.Information about non-IBM products is obtained from the manufacturers of those products or their published announcements. IBM has not tested those products and cannot confirm the performance, compatibility, or any other claims related to non-IBM products. Questions on the capabilities of non-IBM products should be addressed to the suppliers of those products.Prices subject to change without notice. Contact your IBM representative or Business Partner for the most current pricing in your geography.

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The following are trademarks of the International Business Machines Corporation in the United States and/or other countries.

AIX*BladeCenter*CICS*Cognos*DB2*DB2 ConnectDomino*

GDPSHiperSocketsInformixInfoSphereIBM*IBM (logo)*IMS

Lotus*MQSeries*Parallel SysplexPowerVMRACF*

System x*System z*System z10*Tivoli*WebSphere*

z10zEnterprisez/VM*z/VSE



Agenda

Linux Virtualization

Components of Linux on System z Virtualization

DB2 LUW running on Linux for System z



What is Linux

From Wikipedia: Linux refers to the family of Unix-like computer operating systems using the Linux kernel.

A fully-networked 32/64-bit UNIX-like operating system developed by Linus Torvalds

Multi-user, multitask, multiprocessor

Compilers like C, C++, Fortran, Smalltalk, Ada, java

GNU development tools, runtime, and utilities

apache- web server, samba- file and print server, nfs file server, ldap, database

X Windows Graphical User Interface - gnome, kde

Coexists with other operating systems - Runs on multiple platforms

Includes the source code



Linux and IBM

IBM announced commit to Linux-enable all platforms in 1999. Today over 3,000 applications and counting on Linux for System z. Project Green took 3,900 x86 and Unix workloads to 30 System z for 80% energy savings

Power Systems System zSystem x

WebSphere® Tivoli® Lotus®Information Management Rational®

• Full range of virtualization options• Cross-platform consolidations• Choose the platform that bestsuits the workload

Efficiency

• Wristwatches to mainframes• Community drives innovation for scaling both up and out

Scalability

• Enhanced Testing & Cert. • NSA-based Linux Features• Very rapid time to fix if vulnerabilities are discovered

Security

Match the platform to the workload, without adding complexity



Why Customers Are Adopting Linux

Linux offers UNIX customers the flexibility to choose lower cost hardware

Linux offers Windows customers increased flexibility and enhanced security / reliability

Linux offers all customers choice for new workloads through open computing, avoiding lock-in to proprietary hardware or software vendors or architectures

NewWorkloads

UNIXmigrations

Windowsmigrations

Total Cost of Ownership

Flexibility and Choice

Reliability

Security



The Linux Kernel

System z

Legendary dependability, Always on Designed for multiple diverse workloads

executing concurrently Highly scalable – up or out Rich security features Proven high volume data acquisition

and management Advanced virtualization capabilities

Hardware

Platform Specific Code

Platform Specific Code

Linux Applications

Linux Kernel

GNU CompilerGNU

RTLGNU

Binutils

Pure ASCII environment Does not need any other OS to run on a

mainframe Not a replacement for any other OS on IBM

System z Novell-SuSE and RedHat are the supported

distributions

Linux on System z is not a special Linux

Not an emulationNot an emulation

Linux is "hardware agnostic" by designAPI's are consistentAppearance, look, and feel is consistentApplications and skills are portable from platform to platform



Virtualization“Virtualization is the ability for a computer system to share resources so that one physical server can act as many virtual servers.”


IT Optimization on IBM System z



System z Virtualization

Multi-dimensional virtualization technoogy

System z provides logical (LPAR) and software (z/VM) partitioning

PR/SM ( Processor Resource/System Manager ) is a type 1 Hypervisor which enables highly scalable virtual server hosting for LPAR and z/VM Virtual machine environments.

IRD (Intelligent Resource Director) coordinates allocation of CPU and I/O resources among z/OS and non-z/OS LPARs.



Linux on System z is virtualized

Linux on System z is always executed in a virtualized environment.

Linux in an LPAR (native)

Linux as a guest under z/VM

© 2010 IBM Corporation 06/07/11


Some of the Key Components

IFL – Integrated Facility for Linux

Storage

LPAR – Logical Partition

z/VM

Linux guest



Integrated Facility for Linux (IFL)

The Integrated Facility for Linux® (IFL) is a central processor (CP) dedicated to Linux workloads.

Isolated from general use

Supported by z/VM® and the Linux operating system

Can purchase additional processing capacity exclusively for Linux workloads•Without adding general purpose processors•

Operates on full capacity, independent of the general purpose processor speed



Integrated Facility for Linux (IFL)

IFLs (physical processors )

Activated IFL Installed, not activated IFL

System z allows the customer to dynamically activate the number of IFLs needed for their work

Different models have different numbers of IFLs installed

Above: 15 activated IFLs, out of 32 installed



Storage (memory)

Memory is shared between the Linux guests in an LPAR.

Memory is not shared between LPARs

Both the z/VM layer (LPAR) and the Linux (guest) layer have swap.

Most define the guests as to push swapping up to the zVM level and use the linux level swap area as padding for unforeseen high usage.



Logical Partition (LPAR)

Logical partitioning of System Resources

The hardware and firmware that provides partitioning is known as PR/SM™ (Processor Resource/System Manager)

Each LPAR is assigned its share of CPU and Memory

LPARs can be configured as:–Native Linux or z/OS in an LPAR.

–Many Linux guests running under z/VM–

System zSystem z



z/VM

Uses real resources available to create Virtual machines•CPU, Memory, I/O, Network

Virtualization technology•Provides each VM guest with its own working environment •Can run any OS

Provides Guest Support•Capable of running hundreds of Linux VM guests on a single mainframe •Runs with other System z operating systems such as z/OS

z/VM (Control Program (CP))

CMS z/VM z/OSVSE/ESA

OS/390VM/ESA

Linux

Other Operating Systems: TPF, GCS



z/VM - continued

CP (Control Program) – the Hypervisor itself• No high level commands – just basic VM maintenance and control• No files concepts – only virtual devices• No job control – everything is a VM.

CMS (Conversational Monitor System) – Administration Virtual-machine

Interacts with z/VM like a shell or bash in Linux

Edit script like executable files

REXX scripts (EXEC type), file-manager (filelist), text-editor (xedit)

TCP/IP connectivity (TCPMAINT minidisk 592)–Independent copy of OS



Linux Guest

A guest virtual machine runs in the context of a z/VM user ID

Each LPAR runs one OS, If Running z/VM

Z/VM can in turn run many other Operating Systems. These can be linux.

Linux guests are assigned virtual CPUs. 1 or many virtual CPUs per guest.

Tens or hundreds of guests

Resource over commitment (CPU, Memory)



CPU CPU CPU Shared Physical CPUsCPU CPUCPU

z/VM Paging Subsystem

ExpandedStorage Paging Volumes

Virtual CPUs

z/VM Paging Subsystem

ExpandedStorage

Guest Memory

Run multiple copies of z/VM on a single mainframe for enhanced scalability, failover, operations, and energy efficiency

Share CPUs and I/O adapters across all z/VM LPARs, and over-commit memory in each LPAR for added cost effectiveness

LPAR Running z/VM LPAR Running z/VM

Logical CPUs

z/VM-Managed Memory z/VM-Managed Memory

Paging Volumes

Virtualization Components in a Single-System, Multi-LPAR, Linux in z/VM EnvironmentMaximizing Resource Utilization and System Availability



* Source: gomainframe.com Joe Clabby

Up to 100% server utilization compared to 10-20% distributed server utilization*

Shared everything infrastructure allows for maximum utilization of resources–Processors, Memory, Network, Adapters, Cryptography, Devices

Moderate distributed servers Up to 100% utilized System z server

Many applications on one physical System z server

Typically single application per physical server

Virtualization + Consolidation =Maximizing Utilization of Resources with IBM System z

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

App App App App App App App App



0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

App App App App AppApp App App App AppApp App App App App



Customers use Linux® on System z for: Application Serving (OLTP, Web, ERP, etc.)Application Development Data Serving (Warehousing & analytics)Infrastructure Serving (Security, file, print, etc.)

Recommended “best fit” workloads:

Business critical applications: WebSphere®, SAP, Oracle E-Business Suite, …

Development & test: e.g. of WebSphere / Java™ applications

Data services: Cognos®, DB2®, InfoSphere®, Oracle, Informix®, Builders WebFOCUS

Email & collaboration: Lotus Domino®, Lotus® Collaboration products, Web 2.0

Network Infrastructure: FTP, NFS, DNS, etc., Business connectors: WebSphere MQSeries®, DB2 Connect™, CICS® Transaction Gateway, Security Services: Firewall, Proxy, etc.

Percentage of survey respondentsSource: 4Q2010 IBM Market Intelligence

29%

49%

31%

43%

51%

18%

29%

37%

51%

23%

43%

54%

57%

Other workload

Systems Mgmt.

File & Print

Networking

Security

Email/Collaboration

Data Analysis

Data Warehousing

ApplicationDevelop.

CRM/ERP

Batch

Web Serving

OLTP

Consolidate what?



Leverage classic strengths of the System z –High availability–High i/o bandwidth capabilities –Flexibility to run disparate workloads concurrently –Requirement for excellent disaster recovery capabilities–Security

Shortening end to end path length for applications–Co-location of applications–Consolidation of applications from distributed servers–Reduction in network traffic–Simplification of support model

Consolidation Effect–Power requirements–Software costs–People Costs–Real Estate–Workloads requiring EXTREME Flexibility

What Makes A Best Fit Workload for Linux on System z?



DB2 on Linux for System z

DB2 on Linux for System z is NOT DB2 z/OS

DB2 on Linux for System z = DB2 LUW (Linux,Unix, Windows)

Linux is Linux, DB2 LUW is DB2 LUW ...so administration is Common

Examples:

./db2_install - character based installer or ./db2setup GUI db2pd db2ls Fixpaks are also available on FixCentral just like Linux for x86,Windows,Aix Fixes are applied just the same way

Administration is the same … No special DB2, No special Linux.



Monitoring

Same monitoring tools

So what considerations for DB2 running on Linux for System z ?



Considerations and Guidelines for running DB2 on Linux for System z

✔ Check that the kernel jiffies are disabled.echo "0" >/proc/sys/kernel/hz_timer

There are four different I/O schedulers available:noop, deadline,as, cfqnoop, deadline,as, cfqThe default in the distribution is deadline. Don't change the setting to asas on Linux for System z

DIO/AIO are best practices for DB2 LUW but, if your going to use DIO (Direct I/O)

✔ Check that the underlying storage supports this.

SCSI over FCP supports DIO and offers good performance for database servers

Use EXT3 (over reiserfs) , FCP attached SCSI with DIO/AIO whenever possible. .

✔ Disable CMM (Cooperative Memory Management)



Understand the Black Box

Don't treat your storage server like a black box. If you ask your system admin for16 disks, and he gives you 5100-510F. That's the worst case. What's wrong with that ?

Example ESS Architecture



Understand the Black Box



Optimize the storage layout for DB2

– Use as many paths as possible (CHPID -> host adapter)– Spread the host adapters used across all host adapter bays• For ECKD switching of the paths is done automatically• FCP needs a fixed relation between disk and path– Use Linux multipathing for load balancing– Select disks from as many ranks as possible!– Switch the rank for each new disk in a logical volume– Switch the ranks used between servers and device adapters– Avoid reusing the same resource (path, server, device adapter, and disk) as long as possible

Goal is to get a balanced load on all paths and physical disks

In addition striped Linux logical volumes and / or storage pool striping may help to increasethe overall throughput.



Collect System Information

✔Collect dbginfo.sh output and db2support– Proactively in healthy system–When problems occur – then compare with healthy system

dbginfo.sh is a script to collect various system related files, fordebugging purposes. It generates a tar-archive which can beattached to PMRs / Bugzilla entries

part of the s390-tools package in SUSE and recent Red HatDistributions

. It collects the following z/VM information:– Release and service Level: q cplevel– Network setup: q [lan, nic, vswitch, v osa]– Storage setup: q [set, v dasd, v fcp, q pav ...]– Configuration/memory setup: q [stor, v stor, xstore, cpus...]– When the system runs as z/VM guest, ensure that the guest has the appropriate privilegeclass authorities to issue the commands



Collect z/VM performance data

Cheet Sheet at: http://www.vm.ibm.com/perf/tips/collect.html

5 basic steps● create monitor DCSS●setup userid to issue monwrite command●start and configure monitor● start monwrite● stop monwrite and save data

http://www.vm.ibm.com/perf/tips/collect.html



Linux on System z - 10 Years and counting …..



References and Where to find more Info

http://www.ibm.com/developerworks/linux/linux390/index.html

http://www.ibm.com/developerworks/linux/linux390/perf/tuning_diskio.html

Performance considerations for databases on Linux for System z

http://www.vm.ibm.com/education/lvc/

http://linuxvm.org/Present/index.html

http://www.ibm.com/developerworks/linux/linux390/index.html

http://www.ibm.com/developerworks/linux/linux390/perf/tuning_diskio.html

http://www.vm.ibm.com/education/lvc/

http://linuxvm.org/Present/index.html

Documents

A Look into Linux on System z with DB2 · PDF fileA Look into Linux on System z with DB2 LUW This presentation is intended to give the audience a look into the architecture of running