Edit: I still recommend following them.
Originally posted March 31, 2020 on AIXchange
Today’s post features a trio of valuable technical insights, courtesy of IBMers on Twitter.
Chris Gibson alerted me to this IBM technical bulletin (excerpt below) that impacts those running VIO server 3.1.1 and using N_Port ID virtualization (NPIV).
“This is only an issue using NPIV with VIOS 3.1.1. Client LPARs can experience I/O hangs and timeouts under heavy I/O load. We have seen this issue primarily during database backups, but can occur with any large sequential I/Os at high rates.
Affected VIOS Levels and Recommended Fixes
Minimum Affected Level: VIOS 3.1.1.0 devices.vdevice.IBM.vfc-server.rte 7.2.4.0
Maximum Affected Level: VIOS 3.1.1.10 devices.vdevice.IBM.vfc-server.rte 7.2.4.0
Fixing Level: VIOS 3.1.1.20 IJ23222
Interim Fix: iFix
Note: Installation of these fixes requires a reboot.”
On Twitter, Chris noted the summ tool (excerpt below), which is used to summarize and decode AIX I/O error messages:
“DESCRIPTION
“summ” is an AIX only diagnostic tool used to decode fibre-channel and SCSI disk AIX error report entries. It is an invaluable tool that can aid in diagnosing storage array or SAN fabric related problems providing the source of the error.
The script generates single line error messages enhancing the readability of the AIX error report. This is the same tool used by IBM Support worldwide and is considered safe to run in a production environment.
USAGE
The summ command can process results of the AIX error log from a file or from standard input…”
Also from Twitter, Gareth Coates cited his article (excerpt below) that lays out the merits and caveats of connecting baseboard management controller (BMC) systems to your HMCs:
“Summary
Some IBM Power Systems have a flexible service processor (FSP) and these systems are generally connected to, and managed by one or two Hardware Management Consoles (HMCs).
Other Power Systems have a Baseboard Management Controller (BMC) and can be controlled in a number of ways, including the Intelligent Platform Management Interface (IPMI) and the web-based graphical user interface (GUI). It is also possible to connect the system to an HMC. This article discusses the merits of doing so.”
Read the articles, and if you’re on Twitter, follow Chris and Gareth. Both consistently provide valuable technical insights.