Instructions to Manually Enter Boot Options in Grub Shell during Reboot on Oracle Big Data Appliance

Asset ID:	1-79-1983550.1
Update Date:	2016-10-11
Keywords:

Solution Type Predictive Self-Healing Sure

Solution 1983550.1 : Instructions to Manually Enter Boot Options in Grub Shell during Reboot on Oracle Big Data Appliance

Applies to:

Big Data Appliance Hardware - Version All Versions and later
Linux x86-64

Purpose

This document provides instructions on how to manually enter boot options in Grub shell during reboot on Oracle Big Data Appliance(BDA).

Details

Sometimes due to missing latest Kernel/image files or corrupt OS disks the BDA node cannot be booted using the options listed in /boot/grub/grub.conf. In those cases reboot seems to be stuck and ILOM remote console displays 'Error 15: File not found'. Below are the options listed on how to boot the node by manually editing grub menu.

Options Prior to Using Manual Boot Options

Here are the options to try before entering the grub shell

1) Refer to Doc Id 1570447.1 for booting the node into USB rescue mode.

2) If none of the USB Rescue operations work then try to perform a OS boot into old Kernel . Generally options to boot into OLD kernel are listed at the end of the grub menu, so scroll down and try all the OLD kernel OS boot options one by one.

If above options don't work then enter the grub command line shell by entering 'c' from the Grub menu screen

Steps to be followed in Grub Shell during boot

In grub shell TAB completion can be used from step2 to find the directories/kernel/image files available on a particular disk

1) First check on what disk / partition OS or USB bootable disk is present

Lists OS bootable disk

find /grub/grub.conf --> By default should list 2 disks i.e (hd1,0) and/or (hd2,0)

Lists USB bootable disk.

find /boot/grub/grub.conf --> This lists 1 disk generally (hd0,0) or (hd12,0)

2) Confirm if the OS or USB bootable disk resides on the disk / partition listed by above find commands

Note:- Replace * next to hd in below commands with the hd value printed by find commands in step1

For OS

find (hd*,0)/THIS_IS_AN_OS_DISK

For USB

find (hd*,0)/THIS_IS_THE_USB_DISK

The find command/sshould list (hd*,0) entries and shouldn't throw 'Error 15: File not found'. So use different (hd*,0) options in above find command untill you find either OS or USB bootable disk

3) Once you have found the (hd*,0) for either OS or USB bootable disk then follow below steps to either boot into OS or USB mode in grub shell

For OS

grub> root (hd*,0)
grub> kernel (hd*,0)/vmlinuz-<KernelVersion> ro root=/dev/md2 console=tty1 console=ttyS0,9600n8
grub> initrd (hd0,0)/initrd-<KernelVersion>.img
grub> boot

For USB

grub> root (hd*,0)
grub> kernel /boot/vmlinuz-<KernelVersion> ro root=LABEL=BDAUSB console=tty1 console=ttyS0,9600n8
grub> initrd /boot/initrd-<KernelVersion>.img
grub> boot

Note:-If booting using custom boot options from grub shell doesn't seem to help then in Grub menu press 'e' to edit one of the existing options . During edit use (hd*,0) that is listed in step1 in root/kernel/initrd commands

4) Once succesfully booted into the node then correct all the OS disk related issues. Ensure /boot/grub/grub.conf file has valid listings. Then reboot to check if the node can be booted automatically using the grub menu.

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