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
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.