How to trigger SysRq over an HP iLO Virtual Serial Port (VSP) / HP iLO2/iLO3

Environment

• Red Hat Enterprise Linux with serial console configured (see How do I set up a serial terminal and/or console in Red Hat Enterprise Linux?)
• HP Integrated Lights-Out (iLO) firmware 1.80 or higher with Virtual Serial Port (VSP)

Issue

How can a SysRq key combination be sent over an HP iLO Virtual Serial Port (VSP)?

Resolution

The following informations are referring to iLO2 and iLO3.

Through an HP iLO's Virtual Serial Port, the serial BREAK sequence is initiated with Esc + Ctrl + b which triggers the Magic SysRq event. Combine this with the desired SysRq function key.

This function was added in firmware 1.80.

For example, Esc + Ctrl + b followed by m should print the kernel memory details to the console.

• If want to crash the system to generate a vmcore then need to use Esc + Ctrl + b followed by c but in some cases it may not work. So by creating a Hot Key for "sysrq + c" in iLO2 under Remote Console --> Settings --> Hot Keys manual crash can be done. If you are using the Integrated Remote Console (IRC) in iLO2 you will see a toolbar and a button CAD.

For more information, see the "Virtual Serial Port and serial BREAK" section of a related version's iLo manual.

For a general description of the magic SysRq facility, refer to What is the SysRq facility and how do I use it?
For iLO4, refer to How to trigger SysRq from ipmitool and ipmiconsole using the SysRq magic keys over an HP iLO4 ?

Root Cause

The SysRq key is not transmitted over the VSP connection, therefore an escape sequence is required to trigger SysRq on the remote server.

This solution is part of Red Hat’s fast-track publication program, providing a huge library of solutions that Red Hat engineers have created while supporting our customers. To give you the knowledge you need the instant it becomes available, these articles may be presented in a raw and unedited form.