Boot LiveCD Virtual ISO

This page will walk-through booting the LiveCD .iso file directly onto a BMC.

Topics:

Details

Prerequisites

A Cray Pre-Install Toolkit ISO is required for this process. This ISO can be obtained from:

  • The Cray Pre-Install Toolkit ISO included in a CSM release tar file. It will have a filename similar to cray-pre-install-toolkit-sle15sp2.x86_64-1.4.10-20210514183447-gc054094.iso

BMCs’ Virtual Mounts

Most BMCs offer a Web Interface for controlling the node and for providing access to its BIOS and firmware.

Refer to the following pages based on your node vendor for help mounting an ISO image:

HPE iLO BMCs

HPE iLO BMCs allow for booting directly from an HTTP-accessible ISO location.

  1. Enter the Virtual Media URL, select Boot on Next Reset, and click Insert Media.

    Screen Shot of iLO BMC Virtual Media Mount

  2. Reboot by selecting Reset in the top right power menu.

    Screen Shot of iLO BMC Reboot

  3. Open the virtual terminal by choosing the HTML5 Console option when clicking the terminal image in the bottom left corner.

NOTE: It may appear that the boot is stalled at a line of EXT4-fs (loop1): mounted ... or Starting dracut pre-mount hook.... This is the step when it actually begins downloading the ISO’s squashfs root file system and can take a few minutes.

Gigabyte BMCs

Gigabyte BMCs allow for booting over HTTP.

WARNING: Do not try to boot over NFS or CIFS because of problems in the Gigabyte firmware.

  1. Go to the BMC settings and setup the remote ISO for the protocol and node.

    Screen Shot of Gigabyte BMC Virtual Media Settings

  2. Access the BMC’s web interface and navigate to Settings -> Media Redirection Settings -> General Settings.

  3. Enable Remote Media Support and Mount CD/DVD, and then fill in the server IP address or DNS name and the path to the server.

    Screen Shot of Gigabyte BMC General Settings

    NOTE: The Gigabyte URL appears to not allow certain characters and has a limit on path length. If necessary, move or rename the ISO to a location with a smaller file name.

  4. Navigate to Image Redirection -> Remote Images.

  5. Click on the Start button to start the Virtual ISO mount.

    Screen Shot of Gigabyte BMC Start

  6. Reboot the node and select the Virtual CDROM option from the manual boot options.

    Screen Shot of Gigabyte BMC Boot

Configure

The ISO boots with no password, requiring one be set on first login. Continue the bootstrap process by setting the root password following the procedure First Login.

NOTE: The root OS / directory is writable without persistence. This means that restarting the machine will result in all changes being lost. Before restarting, consider following Backing up the Overlay COW FS and the accompanying Restoring from an Overlay COW FS Backup section.

Backing up the Overlay COW FS

Backup the writable overlay upper-dir so that changes are not lost after a reboot or when updating the ISO.

This requires a location to scp a tar file as a backup.

tar czf /run/overlay.tar.gz -C /run/overlayfs/rw .
scp /run/overlay.tar.gz <somelocation>

NOTE To reduce the size of the backup, delete any SquashFS files first, or exclude them in the tar command using --exclude='*.squashfs'. Those will need to be repopulated after restoring the backup.

Restoring from an Overlay COW FS Backup

Restore a backed up tar file from the previous command:

scp <somelocation> /run/overlay.tar.gz
tar xf /run/overlay.tar.gz -C /run/overlayfs/rw
mount -o remount /

If the squashfs files were excluded from the backup, repopulate them following the configuration section.