McNelly: Back From IBM TechXchange
Rob McNelly shares his thoughts on what makes the conference so worthwhile, plus the latest from IBM Support and other observations
I just returned from IBM TechXchange. As always, I am glad I went to the conference and I already look forward to next year. As much as I learn during the sessions and hands-on labs, TechXchange is more than education. Events like this have what I call intangible value. That really just comes down to the opportunity to interact with your fellow attendees. I enjoy meeting new people and catching up with friends I’ve known for years.
Another “intangible” is that each TechXchange offers something special. With this conference in Atlanta, it was an outing to the Georgia Aquarium and the World of Coca-Cola. These get-togethers are yet another way to make memories and connect with coworkers and friends old and new.
As an IBM Champion, there is even another dimension of camaraderie that comes from being part of the sea of Blue Jackets. That last link is video from the 2024 conference. Watch and you’ll get the idea.
If you weren’t there this year, you can still experience IBM TechXchange by viewing general sessions on demand and reviewing recent announcements. And if you’re thinking of attending in the future, this FAQ provides details about the annual conference.
From IBM Support: Power Virtualization Best Practices, and Much More
1) “This document is intended to address IBM POWER processor virtualization best practices to attain best logical partition (LPAR) performance. This document by no means covers all the PowerVM™ best practices so this guide should be used in conjunction with other PowerVM documents.”
2) Using the CLI on the HMC “to balance or choosing the fcs adapters for Live Partition Mobility (LPM)”:
“Provide basic building CLI command example for choosing the fcs adapters for LPM. HMC GUI does not offer the option to select a particular FC port on a particular VIOS on the target system. By default, the HMC orchestrator will automatically select the best options that match the criteria to host the mobile LPAR on the target system.
“There may be a situation in which you may want to use a specific FC port on a target VIOS. In order to do that, migrlpar command can be used with the virtual_fc_mappings option.”
3) If you have DS8000 storage in your environment and are running IBM i, be on the lookout for issues after updating to VIOS 4.1.2.20:
“In an environment where an IBM i client is connected to DS8K storage, I/O operations are generated using the strip/merge mechanism, requiring all I/O requests to be issued against 520-byte sector devices.
“Under this scenario, WRITE operation may fail because the PCI bus driver performs stringent validation of the client’s memory page permissions before processing the request. This additional permission check rejects write requests associated with strip/merge I/O, resulting in write failures on 520-byte devices.”
4) “Vulnerabilities in Rsyslog could cause heap buffer overflow (CVE-2026-78002). Rsyslog is used by AIX as logging daemon.”
“DESCRIPTION: A flaw was found in rsyslog. An unauthenticated remote attacker can trigger a heap buffer overflow in the RainerScript ‘replace()’ function by sending specially crafted syslog messages. This vulnerability arises from an incorrect buffer size calculation during string replacement, causing memory corruption. Successful exploitation can lead to a denial of service (DoS) for the affected system.”
5) I assume if you are a VIOS admin you know how to take a snap but just in case. Related: troubleshooting VIOS snap command issues.
6) “IBM is currently investigating a reported issue affecting systems running IBM i 7.6 TR2 or IBM i 7.5 TR8. Installing the Technology Refresh (TR) can cause a complete loss of network connectivity on partitions using Virtual Ethernet adapter type 268C.”
“Development has identified the root cause of the issue and has released the following HIPER PTFs to address it….
IBM i 7.5: MJ11725
IBM i 7.6: MJ11726
“Please download the appropriate PTF for your IBM i release and apply it along with the cumulative package and group PTFs that contain TR8 (IBM i 7.5) or TR2 (IBM i 7.6)…”
Performance Comparison
I was recently asked to locate the performance comparison document from IBM. This is from July.
Section 1 has SPEC CPU numbers, Section 2 contains rPerf numbers, and Section 3 lists CPW numbers.
The Last UNIX OS
In this observer’s view, the last UNIX OS is AIX:
“With one more operating system gone from the list, there’s now only one UNIX operating system left: AIX. While the registry also lists HP-UX, z/OS, and UnixWare/OpenServer, those either only conform to really old UNIX certifications (from the 90s), or simply aren’t developed anymore (HP sunset HP-UX at the end of last year). Only one operating system version conforms to the latest version of the certification, UNIX 07, and that’s AIX 7.2 TL5 “and later,” which possibly includes AIX 7.3, the most recent version of AIX.
“Not that any of this really matters.”
It may not matter—unless you are running AIX.
Don’t Forget About CDP
Sometimes in this space I will repeat certain technical information. Sometimes I’ll repeat the same info multiple times. This information serves as a reminder—not just for readers, but often for myself.
This latest reminder is that the Cisco Discovery Protocol (CDP) is extremely useful. I was recently in discussion with a network team about which physical port on a Power server was plugged into which physical port on a switch. There were questions about the documentation that was gathered at the time of install, and no one was onsite to verify.
CDP is a very simple method for confirming that ports are properly connected. In this case, in a matter of minutes we were able to determine that the ports we thought were plugged in actually were, as well as identify which switch ports they were connected to.
For more on CDP, read what Chris Gibson has to say about it.