February 22, 2017

SUSE Linux Enterprise 12 Service Pack 2 (SLES 12 SP2) released

SUSE logo

On November 8th 2016 eleven months after the last service pack  SUSE has released the latest updated to their flag ship server distribution. SUSE also has a blog post with some more details.

The kernel level for 12.1 is kernel-4.4.21-69.1. This is a jump in the kernel version from the old 3.12 based kernel. It's the same major kernel level that's being used by Canonical for Ubuntu 16.04. And with that kernel a lot of new functionality is delivered. SUSE and IBM worked hard to ensure that for applications it behaves the same.

What's new (details see documentation and release notes):
Here is my usual summary of links to more information:

February 16, 2017

IBM z Systems Processor Optimization Primer

For z Systems optimizations are essential to keep the consolidation ratio high and make the best use of the hardware. As more and more open source software is ported to Linux on z / LinuxONE Kevin Shum has posted his excellent "BM z Systems Processor Optimization Primer" on developerworks.

There is a long version with all the details and a shorter summary presented at last SHARE.

This is a "must read" for everyone working on compilers and inline assembly on z.

November 4, 2016

Red Hat Enterprise Linux (RHEL) 7.3 released

Red Hat Logo

On November 3rdth 2016 Red Hat released the next regular update to their flag ship operating system.

The kernel level for 7.3 is kernel-3.10.0-514.el7.

Here is my usual summary of links to more information:
From a Linux on z Systems perspective the major enhancements are in the tool chain. The compiler can now can exploit the SIMD instructions of z13.

Also in September Red Hat achieved EAL4+ / common criteria certification for RHEL 7.1:
 (updated 4/11/2016)

October 12, 2016

Oracle 11 R2 now certified on RHEL 7.1 for Linux on z / LinuxONE

The certification is finally done with Oracle and RHEL 7.1. It's highly recommended that you upgrade to the latest fixpacks though. Read more in the IBM Flash or go directly to Oracle support and read the Oracle Note (requires Oracle login):
  • 1967531.1: "Requirements for Installing Oracle RDBMS on RH7 on IBM: Linux on System z (s390x)" - which has detailed installation instructions, which are a must read before trying to install. 
As usual with Oracle certifications RHEL 7.1 is the minimal level required.

September 22, 2016

IBM Doc Buddy now has Linux and z/VM messages

IBM Doc Buddy start screen
IBM Doc Buddy is a mobile app that allows for retrieving explanation on IBM z error message codes. Now you can also get Linux and z/VM messages offline explained with this app.
You can get the application from Apples Appstore or from Google Play, depending on the mobile device you use.

The information is the same as in the books (note that Ubuntu and Red Hat don't have included the message numbers yet):
You first have to download the messages for the "component" you want. To do that touch the button in the upper left corner and then select the respective component. Then you can start typing into the search field and select the message of interest:

IBM Doc Buddy - setup screen
Setup screen

IBM Doc Buddy - Add component
Select component

IBM Doc Buddy - Search

IBM Doc Buddy - example result
Get result (can be scrolled!!)

September 19, 2016

Performance whitepapers for IBM Enterprise Content Management with Filenet for Linux on z Systems

IBM has a good portfolio of Enterprise Content Management (ECM) products. One of them is IBM FileNet. Storing a lot of data and finding content is something that z Systems does really well. So after the first whitepaper concentrating on FileNet there is a new paper that adds IBM Content Navigator and IBM Spectrum Scale (formerly known as GPFS) to the mix.

This new paper is split into two parts:
  • The first part with the title "IBM Enterprise Content Management for Linux on z Systems Scale-Out Case Study (Part 1): Single ECM Node with XFS and IBM Spectrum Scale 4.2" is available on Partnerworld (direct pdf download).
  • I'll update this post as soon as the second part is available

September 12, 2016

Java performance improvements

IBM continues to improve the performance of Java on the mainframe. To show this I've taken a snapshot of the performance improvements during the latest Java releases. The operating system was a SLES 12 SP1 and this was run on  a z13 LPAR with 6 cores and SMT enabled.

java performance improvements on Linux z

As you can see you there is a solid 33% percent improvement going from the first Java 7 version to the latest Java 8 SR3 FP10 version.

So the first recommendation when you are having Java performance problems with Linux on System z is to try a more advanced Java version.

September 8, 2016

New whitepaper "Hardware cryptographic support of IBM z Systems for OpenSSH in RHEL 7.2 and SLES 12 SP1"

There is a new whitepaper on TechDocs, that describes the HowTo setup the Linux distributions RHEL 7.2 and SLES 12 SP1, so that OpenSSH (and all workloads using this) really benefit from the hardware encryption delivered with System z.

One of their key outcomes is that you either need to specify the accelerated ciphers explicitly or put them at the top of the search order of OpenSSH.

Abstract: "This article summarizes our experiences with the configuration and usage of OpenSSH using hardware cryptographic support of IBM z Systems. We report our findings in the areas of performance and throughput improvement. Our positive experience indicates that you should make use of this capability when using OpenSSH." 

September 5, 2016

Ubuntu 16.04.1 and kernel support map

Ubuntu logo

End of July Canonical released the fix update for their first mainframe release. No new features but a lot of fixes, for Linux on z many installation fixes. If you are using (or planning to use) Ubuntu 16.04 LTS it's time to think about the life cycle.  Here is the support map from Ubuntu Wiki:

Ubuntu 16.04 kernel support schedule
Source: Ubuntu Wiki as of 9/5/2016, License: Creative Commons Attribution-ShareAlike 3.0 License

My recommendation is the following:
  • For production use stay with 16.04.1 stream for the life of the product. Plan for a check point in spring 2018 and check if you need the additional hardware enablement delivered with the 16.04.5 kernel. 
  • For development use you probably want the latest kernel anyhow. There 16.04.2-16.04.4 are valid choices. However I'd rather upgrade everything and go with the 16.10, 17.04, 17.10 versions. This will give you the latest versions of all the open source packages as well.

July 6, 2016

z13 feature exploitation - which distribution levels are required

In this post I'll try to summarize which distribution levels, packages, APARs, PTFs etc are needed to exploit a given z13 (performance) function. I expect this to change over time, so please revisit for updates.

For the virtualization layers I use the label "(guest)" for enablement of guest exploitation. So you need at least the given version of the Hipervisor to exploit a certain function in the guest. Of course you also need the respective guest support.

All version levels in the table are minimum levels.

 Feature  Red Hat  SUSE  Ubuntu  z/VM
SMT 7.2 12 SP1 16.04 6.3+
SIMD: kernel support – compiled SIMD apps can run 7.2 12 SP1 16.04 6.3+(3) 1.1.1 1.1.1
z13 tool chain support (compiler, binutils) tbd 12 SP1 16.04 6.3+ 1.1.0
PCI: RoCE 10 Gb Ethernet 7.2(1) 12 SP1 16.04
PCI: RoCE 10 Gb OFED stack 7.2(1) 16.04
PCI: zEDC Java(4) 7.2(1) 12 SP1 16.04
PCI: zEDC zlib preload library (1)(2) (2) 16.04

(1) fixes coming, maybe in next fix pack
(2) RYO lib from https://github.com/ibm-genwqe/genwqe-user
(3) z/VM APAR VM65733 required
(4) Java 7 SR9FP30, Java 7.1 SR3FP40, Java8 SR3

(updated 9/30/2016)