chshut - Control the system shutdown actions

Ubuntu 22.04 LTS LPAR mode z/VM guest KVM guest

Use the chshut command to change the shutdown actions for specific shutdown triggers.

The shutdown triggers are:

halt
poff
reboot

The shutdown triggers restart and panic are handled by the dumpconf service script, see Using the Dump Tools, SC33-8412 for details.

Linux® on IBM® Z performs shutdown actions according to sysfs attribute settings within the /sys/firmware directory structure. The chshut command sets a shutdown action for a shutdown trigger by changing the corresponding sysfs attribute setting.

chshut syntax

Where:

halt: sets an action for the halt shutdown trigger.
poff: sets an action for the poff shutdown trigger.
reboot: sets an action for the reboot shutdown trigger.
ipl: sets IPL as the action to be taken.
reipl: sets re-IPL as the action to be taken.
stop: sets stop as the action to be taken.
vmcmd "<cp_command>": sets the action to be taken to issuing a z/VM® CP command. The command must be specified in uppercase characters and enclosed in quotation marks. To issue multiple commands, repeat the vmcmd attribute with each command.
-h or --help: displays help information for the command. To view the man page, enter man chshut.
-v or --version: displays version information.

Examples

These examples illustrate common uses for chshut.

To make the system start again after a power off:
```
# chshut poff ipl
```
To log off the z/VM guest virtual machine if the Linux poweroff command was run successfully:
```
# chshut poff vmcmd LOGOFF
```
To send a message to z/VM user ID OPERATOR and automatically log off the z/VM guest virtual machine if the Linux poweroff command is run:
```
# chshut poff vmcmd "MSG OPERATOR Going down" vmcmd "LOGOFF"
```