Troubleshooting

iPXE

If you’re using iPXE to boot (the default), you can get a command prompt by pressing with C-b during boot.

From the iPXE command prompt, you can run the same commands from default.ipxe (or dracut.ipxe) to troubleshoot potential boot problems.

For example, the following commands perform a (relatively) normal Warewulf boot. (Substitute your Warewulf server’s IP address in place of 10.0.0.1, update the port number if you have changed it from the default of 9873, and substitute your cluster node’s MAC addres in place of 00:00:00:00:00:00.)

set uri http://10.0.0.1:9873/provision/00:00:00:00:00:00
kernel --name kernel ${uri}?stage=kernel
imgextract --name container ${uri}?stage=container&compress=gz
imgextract --name system ${uri}?stage=system&compress=gz
imgextract --name runtime ${uri}?stage=runtime&compress=gz
boot kernel initrd=container initrd=kmods initrd=system initrd=runtime

  • The uri variable points to warewulfd for future reference. This includes the cluster node’s MAC address so that Warewulf knows what container and overlays to provide.

  • The kernel command fetches a kernel for later booting.

  • The imgextract command fetches and decompresses the images that will make up the booted noe image. In a typical environment this is used to load a minimal “initial ramdisk” which, then, boots the rest of the system. Warewulf, by default, loads the entire image as an initial ramdisk, and also loads the system and runtime overlays at this time time.

  • The boot command tells iPXE to boot the system with the given kernel and ramdisks.

Note

This example does not provide assetkey information to warewulfd. If your nodes have defined asset tags, provide it in the uri variable for the node you are trying to boot.

For example, you may want to try booting to a pre-init shell with debug logging enabled. To do so, substitute the boot command above.

boot kernel initrd=container initrd=kmods initrd=system initrd=runtime rdinit=/bin/sh

Note

You may be more familiar with specifying init= on the kernel command line. rdinit indicates “ramdisk init.” Since Warewulf, by default, boots the node image as an initial ramdisk, we must use rdinit= here.

GRUB

If you’re using GRUB to boot, you can get a command prompt by pressing “c” when prompted during boot.

From the GRUB command prompt, you can enter the same commands that you would otherwise find in grub.cfg.ww.

For example, the following commands perform a (relatively) normal Warewulf boot. (Substitute your Warewulf server’s IP address in place of 10.0.0.1, and update the port number if you have changed it from the default of 9873.)

uri="(http,10.0.0.1:9873)/provision/${net_default_mac}"
linux "${uri}?stage=kernel" wwid=${net_default_mac}
initrd "${uri}?stage=container&compress=gz" "${uri}?stage=system&compress=gz" "${uri}?stage=runtime&compress=gz"
boot

  • The uri variable points to warewulfd for future reference. ${net_default_mac} provides Warewulf with the MAC address of the booting node, so that Warewulf knows what container and overlays to provide it.

  • The linux command tells GRUB what kernel to boot, as provided by warewulfd. The wwid kernel argument helps wwclient identify the node during runtime.

  • The initrd command tells GRUB what images to load into memory for boot. In a typical environment this is used to load a minimal “initial ramdisk” which, then, boots the rest of the system. Warewulf, by default, loads the entire image as an initial ramdisk, and also loads the system and runtime overlays at this time time.

  • The boot command tells GRUB to boot the system with the previously-defined configuration.

Note

This example does not provide assetkey information to warewulfd. If your nodes have defined asset tags, provide it in the uri variable for the node you are trying to boot.

For example, you may want to try booting to a pre-init shell with debug logging enabled. To do so, substitute the linux command above.

linux "${uri}?stage=kernel" wwid=${net_default_mac} debug rdinit=/bin/sh

Note

You may be more familiar with specifying init= on the kernel command line. rdinit indicates “ramdisk init.” Since Warewulf, by default, boots the node image as an initial ramdisk, we must use rdinit= here.