Base Users Guide: 
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There are two scenarios in which you need to add extra kernel boot parameters: 1) during installation, and 2) during normal boot. For both scenarios, we will use the example of adding the kernel boot parameter: "ucsd=rocks".
The boot action of a node is controlled by the Rocks command line. For example, the following lists what the nodes will do on their next PXE boot:
# rocks list host boot HOST ACTION vi-2: ------ compute-0-0: os compute-0-1: os |
We see that compute-0-0 will boot the "os", that is, it will boot off its local disk. Another common action is "install" which means the node will boot the installation kernel and install itself on the node's next PXE boot.
To list all the possible boot actions for a node, execute:
# rocks list bootaction ACTION KERNEL RAMDISK ARGS install: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 install headless: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 headless vnc memtest: kernel memtest ------------------- -------------------------------------------------------------------------------------- os: localboot 0 ------------------- -------------------------------------------------------------------------------------- pxeflash: kernel memdisk bigraw pxeflash.img keeppxe rescue: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 rescue |
To change a node's boot action to "install", execute:
# rocks set host boot compute-0-0 action="install" |
Then we see that correct boot action has been applied:
# rocks list host boot HOST ACTION vi-2: ------- compute-0-0: install compute-0-1: os |
Now to change the kernel boot parameters for the installing kernel, we'll need to add an action. We'll create a new action called "install ucsd" and add our boot flag "ucsd=rocks" to the end of the kernel boot parameters:
# rocks add bootaction action="install ucsd" kernel="vmlinuz-5.2-i386" ramdisk="initrd.img-5.2-i386" \ args="ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 ucsd=rocks" |
We now see that "install ucsd" is an available action:
# rocks list bootaction ACTION KERNEL RAMDISK ARGS install: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 install headless: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 headless vnc install ucsd: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 ucsd=rocks memtest: kernel memtest ------------------- -------------------------------------------------------------------------------------- os: localboot 0 ------------------- -------------------------------------------------------------------------------------- pxeflash: kernel memdisk bigraw pxeflash.img keeppxe rescue: vmlinuz-5.2-i386 initrd.img-5.2-i386 ks ramdisk_size=150000 lang= devfs=nomount pxe kssendmac selinux=0 noipv6 rescue |
To set the install action for compute-0-0 to "install ucsd", execute:
# rocks set host installaction compute-0-0 action="install ucsd" |
Then we see that correct boot action has been applied:
# rocks list host HOST MEMBERSHIP CPUS RACK RANK RUNACTION INSTALLACTION vi-2: Frontend 1 0 0 os install compute-0-0: Compute 2 0 0 os install ucsd compute-0-1: Compute 2 0 1 os install |
The next time compute-0-0 is installed, it will use the "install ucsd" profile.
To get the current parameters that will be appended to the default kernel boot parameters, execute:
# rocks report host bootflags rocks-168: dom0_mem=1024M compute-0-0: dom0_mem=1024M |
Then, to add our boot flag of "ucsd=rocks", execute:
# rocks set host bootflags compute-0-0 flags="dom0_mem=1024M ucsd=rocks" |
To check to make sure the flag has been added to the database, execute:
# rocks report host bootflags rocks-168: dom0_mem=1024M compute-0-0: dom0_mem=1024M ucsd=rocks |
To apply the flags to the running kernel, you'll need to reinstall the compute nodes. For example, you'll need to reinstall compute-0-0 in order to apply "ucsd=rocks" to its kernel boot parameters. After compute-0-0 is reinstalled, you can check that the new kernel boot parameters have been applied by logging into compute-0-0 and executing:
# cat /proc/cmdline ro root=LABEL=/ dom0_mem=1024M ucsd=rocks |