Node Boot Style#

A node's boot style is controlled using the _boot_style reserved attribute.

To switch the _boot_style for a node, run the following command:

cw-nodectl -in10 set _boot_style=roram

To set the _boot_style for all nodes in the default attribute group, set the attribute there instead using:

cw-attribctl -iDefaultAttribs set _boot_style=roram

The following boot styles are available:

  • rwram: Default boot style. Downloads and unpacks the OS image to temporary space within RAM. Uses the most RAM, but is most resiliant to issues.

  • roram: Downloads the OS image to RAM overlay. This boot style has the same effect as rwram, but uses less RAM because the image remains compressed. Not compatible with some applications, such as Docker.

  • iscsi: The OS image is shared as a disk by the head nodes. Compute nodes have a read-only mount and overlay. Only the written files are saved in local RAM. Requires stable network connection to head nodes.

  • next: When booting, the boot order goes to the next boot device. Typically nodes boot network followed by disk. By setting the boot style to next, network boot is skipped and the node boots from hard drive.

  • disked: Requires setting the _disk_root reserved attribute to a local drive partition name. Boots from a local disk rather than RAM. When booting, the partition is wiped, a file system is created, and the image is unpacked to that location. Using this option reserves RAM space for computation. See Booting From Local Storage Cache for details.

  • sanboot: iPXE feature. If the _ipxe_sanboot reserved attribute is not set to a local disk or partition name, the device boots from the first disk. If a local disk or partition name is provided or if you provide other sanboot arguments, you can boot from another drive or partition. Used on systems where the next boot style is not a good option.

  • live: If you have a boot configuration that is based on an ISO, you can live boot that ISO on the device as though it is booted from the local drive. This boot style can be useful when setting up Kickstart or when creating an image manually.