This section explains how to boot, shutdown and reboot sNow! Compute Nodes
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Boot from local disk (localboot)

In order to boot the compute nodes from the OS installed in the local disk, run the following command:

snow boot <compute_node(s)> localboot

This assumes that deployment is used as provisioning mechanism and the nodes instructed to boot are already deployed. Unless the compute nodes configuration have been modified the provisioning based on deployment sets the default boot image to localboot, which enables the compute nodes to boot from the local disk.

Boot from Diskless Image

In order to boot the compute nodes from a specific OS image, run the following command:

snow boot <compute_node(s)> <image_name>

This assumes that the compute nodes will be able to boot via PXE by using a diskless image. It is recommended to setup the default OS image. You can setup that globally in snow.conf by setting the image name as the value of DEFAULT_BOOT. Otherwise, you have setup the default boot per node basis, by using the command snow set node --default_boot <image_name> (more information available in Compute Node Setup section).

Reboot

The following command allows rebooting a specific compute node:

snow reboot <compute_node(s)>

Reset

The following command forces rebooting a specific compute node:

snow reset <compute_node(s)>

Shutdown

The following command allows shutting down a specific compute node:

snow shutdown <compute_node(s)>

Destroy

The following command forces to stop a specific compute node simulating a power button press:

snow destroy <compute_node(s)>

Power Off

The following command initiates a soft-shutdown of the OS via ACPI for compute node:

snow poweroff <compute_node(s)>
Differences between shutdown, destroy and poweroff:
shutdown requires access to the OS in order to be able to trigger ‘systemctl poweroff’ command.
destroy forces to stop specific node simulating a power button press. This is performed at the IPMI level in those situations where the system is up but is not responsive (i.e. a boot failure).
poweroff initiates a soft-shutdown of the OS via ACPI. This is useful when for some reason you don’t have access through SSH but you have access from console (i.e. the system booted without network configuration).