What is the keyboard combination for SysRq on a Thinkpad T400p?

[Yochanan]

@chesc

Is there a way REISUB could have been disabled?

It’s not enabled by default.

@Fabby

How to invoke the REISUB procedure?
First we have to unlock the SysRq key so:

• Execute echo kernel.sysrq=1 | sudo tee --append /etc/sysctl.d/99-sysctl.conf

Or…

@Fabby

• • Add to your /etc/default/grub in the GRUB_CMDLINE_LINUX_DEFAULT parameter the sysrq_always_enabled=1 variable instead of executing the above command