November 4, 2016

Red Hat Enterprise Linux (RHEL) 7.3 released

Red Hat Logo

On November 3rd 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 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
(3) z/VM APAR VM65733 required
(4) Java 7 SR9FP30, Java 7.1 SR3FP40, Java8 SR3

(updated 9/30/2016)

June 25, 2016

Fedora 24 for IBM z Systems and Linux ONE released

Fedora logo

The new Fedora 24 for z Systems / s390x / LinuxONE was released 6/21/2016 together with the Intel version. Thanks to the Fedora team for closing the time gap between the architectures! The kernel level is kernel-4.5.5-300.

As usual the download is available from the Fedoraproject site and the respective mirrors and known issues  are covered in the wiki.

June 9, 2016

How to submit requirements for LinuxONE, Linux on z Systems, z/VM and KVM on z Systems

Request for Enhancement IBM Community

KVM as well as LinuxONE is now part of the " Request for Enhancement (RFE) Community". So as described in my earlier post you can now also submit requirements for LinuxONE and KVM to IBM. To do this open the  community start page and then select  the "Submit" tab.
After entering in your IBM ID, you can fill in your requirement. In the product pull down please select one of:
  • Linux on System z
  • IBM LinuxONE
  • KVM for IBM z Systems
  • z/VM
Fill in the other fields as good as you can and then click on submit.

Canonical is handling requirements for the Ubuntu distribution through Launchpad. Open a bug there, put requirement in the title and tag it with s390x.

Red Hat has a defined RFE process for their customers. So after logging into RHN follow the instructions to submit a request.

SUSE requirements can be submitted to their sales reps as well as using  the "feedback" button at the bottom of the SUSE Linux Enterprise Server for System z web site.

(Updated 6/28/2016)

June 1, 2016

The Ubuntu Mainframe Cookbook

If you liked the Virtualization Cookbooks for Red Hat and SUSE and you are looking at Ubuntu right now then maybe you are interested in Mike MacIsaac's latest book: The Ubuntu Mainframe Cookbook.

May 20, 2016

Red Hat Enterprise Linux 6.8 released

On May 11 2016 Red Hat has announced the availability of RHEL 6.8. This marks the transition into what in Red Hat's product life cyle is called production phase 2. The kernel level is now kernel-2.6.32-642.el6, for the main bug fixes see the kernel update description.

As usual there are the release notes and the technical notes in two separate documents. The complete documentation can be reached from the Red Hat documentation page (you need to select "6" on the left bar).

The IBM documentation for RHEL 6.4 on developerworks still applies for this release.

From a technical perspective the most important part are the z13 performance patches, which will make certain workloads run faster than on previous releases.

May 4, 2016

dasdfmt performance

This week I got asked multiple times on how to speed up the formatting of classical ECKD DASDs. The command to use is dasdfmt which is part of the s390-tools package. In the newer distributions there is an option called --requestsize=..... which allows to specify the number of cylinders to use in each format step. Basically it's the amount of parallelism that should be used.
The drawback is that on classical ECKD devices you can only have one outstanding IO. So to take advantage of this you need (Hyper)PAV installed and enabled for the DASD you want to format. For the comparison here I used one base device and 16 aliases and a 3390 mod 9 DASD with 10017 cylinders. Varying the requestsize from 1 to 16 on Ubuntu 16.04 I got the following throughput:

As you can see you can get a decent speedup. You can get well under 10s in my example. So give it a try. 

April 21, 2016

Ubuntu 16.04 LTS available for LinuxONE and z Systems

Today Canonical announced the availability of Ubuntu 16.04 LTS including full support for z Systems and LinuxONE. Welcome to the platform!
Besides bringing tons of packages there is a fundamental change in pricing. It's no longer IFL based but rather based on a drawer. See the Ubuntu blog entry below.

Link collection to useful information:
Video "Ubuntu + IBM LinuxONE™ explained by Mark Shuttleworth, Canonical "

(updated 6/5/2016)

April 6, 2016

Ubuntu 16.04 LTS beta is available for z Systems

Canonical made the beta of the upcoming Ubuntu 16.04 distribution available. So feel free to download and try.

March 21, 2016

KVM for IBM z Systems - version 1.1.1 GA

After the announcement in February, KVM for IBM z Systems 1.1.1  is now generally available. This is the second release, and it is expected that a new update is going to be released every half year.   

Here are a few links for further details:
Note: there is already the first fixpack available on Fix Central. When you start, please install the latest fixpack!

If you encounter any problems, please open a PMR with IBM. 

(updated 3/23/2015) 

March 3, 2016

New Open source packages for Linux on z

List of validated open source packages for Linux on z Systems

One of the FAQs after launching LinuxONE is the question: what of the currently popular applications stacks etc has been ported to Linux on z?
There is a community called "IBM LinuxONE and Linux on IBM z Systems Open Source Ecosystem" that in the forum has a list of projects ported/tested. Don't get confused by the date of the entry, look at the bottom for the latest update.
If you are missing something, feel free to ask the question in the forum.

Best session at Winter SHARE 2016: "I Just Bought an IBM z890 - Now What?"

Today at SHARE I had the remarkable experience to listen to a session Connor Krukosky. He's a 18 year old student that bought a z890 on eBay. Here is his story. The first operating system he got running was Linux. Some of the stumbling blocks (e.g. writing a IOCDS) he mentions reminded me from the time 17 years back, when I learned the same things the same way. SHARE has recorded the session. The video is now on YouTube:

(updated 3/29/2016)

February 26, 2016

IBM Interconnect 2016 news

This week at Interconnect in 2016 there were some good demos that I want to share. In the key note presentation from Ross Mauri "Master Hybrid Cloud, Defend Against Cyber Threats with IBM z Systems and IBM LinuxONE"

there are some interesting demonstrations: the "shopping experience" demo for LinuxONE starts at 25:15 and blockchain demo for LinuxONE starts at 51:22.

February 24, 2016

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."

February 22, 2016

KVM for IBM z Systems V1.1.1 and KVM survey

Together with the z13s IBM also announced the next version KVM for IBM z Systems V1.1.1 (search for 1.1.1 in the announcement). It will be available March 18, 2016. Here are some of the enhancements it will offer:
  • Simultaneous multi threading (SMT) support in the host. The guests don't see the difference
  • Support for the Vector Facility introduced in z13(s) (SIMD) to accelerate string operations and calculations
  • Hypervisor enhancements including support for iSCSI and NFS
  • Unattended installation capability of hypervisor for ease of installation
As this new product is continue to evolve at a fast pace, IBM has put up a survey for everyone interested to provide their input.

For the popular UI virt-manager a "howto build" is available. 

(updated 2/25/2016)

February 17, 2016

z13s videos

Announcement & retail demo: The retail demo starts around 17:50 into the video 

Other marketing videos: 

February 16, 2016


IBM announced the new version of the business class  mainframe called z13s.  This is the successor to the zBC12. You can find the detailed announcement letter here.
glas model picture for z13s
z13s glas model - photo Michael Storzer

From a Linux perspective the IBM tested platforms has been updated to include z13s. SUSE has published the certifications:
Also announced are
Useful links:
(updated 10/21/2016)