New whitepaper: "High Availability with KVM for IBM z Systems"

There is a new white paper on IBM Techdocs that covers High Availability aspects for KVM on z.
From the abstract: "This white paper focuses on considerations for setting up a highly-available KVM for IBM z environment hosting your business applications. With IBM’s investments in z Systems reliability, availability and serviceability, z Systems is an excellent platform to host a High Availability KVM for IBM z environment."

New Whitepaper "z/VM 6.3 HiperDispatch - Polarization Modes and Middleware Performance"

This white paper looks at the effect of using the HiperDispatch feature (introduced with z/VM 6.3) with a mixed Linux workload. It also provides results for applying the scalability APAR VM65586.
 The improvements in the mixed workload including Websphere and Oracle DB shows that this APAR is not only valuable for z13, but rather for everyone with a larger number of IFLs. And if you are still running an old pre 6.3 z/VM release, now is the time to upgrade!

New Whitepaper "IBM Cognos Business Intelligence 10.2.1 for Linux on System z - Performance and z/VM Resource Management"

IBM Cognos Business Intelligence is an interesting workload for zLinux environments. This new whitepaper covers setup and some of the performance and tuning aspects for this in a zLinux / z/VM environment.
As an add on it also takes a look at the z/VM resource manager (VMRM) for helping to distribute the CPU capacity between competing workloads.

New Whitepaper covering IBM Filenet P8 on zLinux

IBM Filenet P8 has been available for zLinux for quite some time. It's a really scalable document management, content lifecycle, and workflow platform. This is then used by Enterprise Content Management or Business Platform Management software. With that solution you can keep all the data secured on System z.
The new whitepaper "Linux on System z and IBM FileNet P8 5.1 Setup, Performance, and Scalability" (pdf version) covers in the performance and scalability on zLinux. It turns out that this is a solution well suited for the System z platform.

New Whitepaper "Implementing A Web Interface For The Linux Health Checker"

The Linux Health Checker is an IBM initiated open source project hosted on Sourceforge. It's a command line tool with an increasing number of plugins to find potential problems and wrong configurations before anything happens.
The new whitepaper describes how to automate the command line tool and collect all the reports from the whole z/VM in a singe web interface.

New performance whitepaper on exploiting System z crypto hardware with WebSphere 8 for Linux on System z

System z offers hardware accelerations for all kinds of cryptographic operations. The new whitepaper "IBM WebSphere Application Server Version 8 for Linux on IBM System z – SSL Setup and Performance Study" shows how to set up WebSphere and Linux.
The performance numbers are quite impressive, especially for RSA 4096.

High Availibility solutions for Websphere MQ and Linux on System z

The standard approach for achieving high availability with Websphere MQ is to use a High Availability Manager and a shared DASD. The following whitepapers describe this for the available options:

• High Availability Solution for WebSphere Message Queue in a single instance queue manager configuration using Tivoli SAfMP and a shared DASD device
• High Availability Solution for WebSphere Message Queue in a Single Instance Queue Manager Configuration using HAE and a Shared DASD Device
• High Availability Solution for WebSphere Message Queue in a Single Instance Queue Manager Configuration Using Linux HA and a Shared DASD Device

Whitepapers for Live Guest Relocation and z/VM 6.2

(updated 9/2/2013)

The Platform Test team for System z has published two new white papers that should help readers to get a smooth start with Live Guest Relocation in z/VM 6.2.

• Early Experiences with z/VM 6.2 and Live Guest Relocation: moving from CSE to SSI:  This paper describes the installation differences to a classical z/VM installation as experienced by the test team. It's not replacing the product documentation but rather augmenting it.
• z/VM Single System Image Cluster Live Guest Relocation with HiperSockets: Exploitation via Dynamic Routing: Live Guest Relocation and HiperSockets look like a contradiction at the first glance. If you move a z/VM  guest off the CEC - what do you do with this network interface? This paper offers a clever approach to this problem, while keeping the solution as flexible as possible. 
• z/VM Migration: Migrating the User Directory and RACF Environment: This document describes an automated migration to a new SSI environment using REXX scripts.

Performance results are available here:

• z/VM 6.2 Live Guest Relocation with Linux Middleware: This paper looks at a Java application and the impact and performance for moving it in various scenarios. It also gives recommendations on how to best set up z/VM for Live Guest Relocation
• z/VM 6.2 Live Guest Relocation with Linux Middleware - Various Workloads: This is the follow on paper to the one above with additional workloads and more in depth analysis. Besides looking deeper at Java it also uses a OLTP database workload and a file system workload for comparison and analysis.
• The z/VM performance update (starting at page 16) at SHARE contains quite some performance results for LGR.

There are also two Redbooks published:

• An Introduction to z/VM Single System Image (SSI) and Live Guest Relocation (LGR): This really is an introduction to the new z/VM functionality
• Using z/VM v 6.2 Single System Image (SSI) and Live Guest Relocation (LGR): This book is a little bit more advanced with concrete examples of moving e.g. an Websphere and a DB2 guest under load.

Even though the official term for mobility is "Live Guest Relocation" you might find also references to "Live Guest Mobility" or "Dynamic Relocation" or just "Mobility in z/VM".

New Whitepaper "Using the Linux cpuplugd Daemon to manage CPU and memory resources from z/VM Linux guests"

CPU and memory resources are normally shared in a virtualized environment. Therefore multiple guests are fighting for the same resources. Before the release of SLES11 SP2 and RHEL6.2 the automatic management of the number of virtual CPUs and the memory used in a virtual guest has been quite limited. Each system was requiring special attention and tuning of cpuplugd, the daemon that does the autonomic management in Linux on System z. Even then it had to be disabled for many systems.
The newer releases have a vastly improved daemon, that now allows for more detailed rules for adding and removing CPUs and memory to a guest. The drawback of more tuning knobs are more tuning knobs.
So this whitepaper tries to develop a recommended set of parameters to get the most benefit with the least effort. Furthermore results of measurements and experiments are shown together with the used parameters for advanced tuning.
Be aware that if you want cpuplugd to control memory and you run with more than one virtual CPU, you really want the fix for APAR VM65060 installed.
Also there has been a bug discovered in the base of SLES11 and RHEL 6 that's been fixed with maintweb kernel 3.0.42-0.7.3 for SLES 11 and the base RHEL 6.4 for Red Hat.

Whitepaper update: "Explore Decimal Floating Point support in Linux on System z"

Since a few years no System z offers hardware support for decimal floating point operations as defined by IEEE 754-2008. This allows for exact and very fast calculations in the decimal (and not the normal binary) system in the processor.

You can check if your system does support this by
cat /proc/cpuinfo | grep features
features        : esan3 zarch stfle msa ldisp eimm dfp edat etf3eh highgprs

If you see a "dfp" in included in the feature list, your system is enabled for decimal floating point.

The new instructions can be used from Java and C/C++. For Java use the java.math.BigDecimal class in a recent JVM. Other languages need compiler and library support and language extensions. ISO/IEC TR 24732 defines this for C and ISO/IEC TR 24733 for C++.

This updated whitepaper describes the details for what's needed to exploit this feature. It includes some performance results as well and all the necessary references

New Whitepaper: "WebSphere Application Server Horizontal Versus Vertical JVM Stacking Report"

This new whitepaper addresses the question if one should do a 1:1 consolidation or putting more than one server into a zLinux guest from a performance perspective. The sweet spot for the setup used here was at 10 JVMs per guest.
It also looks at the alternatives for sharing the application binaries between guests using Discontiguous Saved Segments (DCSS) and shared z/VM minidisks. Here it turned out that starting from 10 guests the DCSS setup was more efficient.

New whitepaper: "Sharing A WebSphere Application Server V8 Installation Among Many Linux for IBM System z Servers"

In the new white paper "Sharing A WebSphere Application Server V8 Installation Among Many Linux for IBM System z Servers" you find a hands on description on a more complex WAS server setup. This is the update of the white paper covering WebSphere Application Server V7.
So if you want to install once and use the installation in many Linux guests take a look at this.