How to Setup OS to Boot from A Cloned LUN with Multipath to SAN (Doc ID 822988.1)

Last updated on MARCH 08, 2017

Applies to:

Linux OS - Version Oracle Linux 5.3 and later
Information in this document applies to any platform.
Linux Kernel - Version: 5.3


Goal

The scenario is: You have a server booting from a multipathed LUN and the server works fine. You cloned the LUN into a new one, and presented it to the same server to replace the original one. When starting up the server, you got kernel panic on the screen:

root (hd0, 0)
Filesystem type is ext2fs, partition type 0x83
kernel /vmlinuz-2.6.180-128.el5 ro root=/dev/mapper/mpath0p3 rhgb quiet crashkernel=128@16M
[Linux-bzImage, setup=0x1e00, size=0x1cb41c]
initrd /initrd-2.6.18-128.el5.img
[Linux-initrd @ 0x378e8000, 0x607753 bytes]


Red Hat nash version 5.1.19.6 starting
No devices found
Uname to access resume device (/dev/mapper/mpath0p2)
mount: could not find filesysetm '/dev/root'
setuproot: moving /dev/ failed: No such file or directory
setuproot: error mounting /proc: No such file or directory
setuproot: error mounting /sys: No such file or directory
setuproot: mount failed: No such file or directory
Kernel panic - not syncing: Attempted to kill init!


This issue was because the ramdisk/initrd still use the old LUN's SCSI ID to create the multipath pseudo device on new LUN, therefor root filesystem can not be mounted.
This note illustrate the procedure to fix this problem.

Solution

Sign In with your My Oracle Support account

Don't have a My Oracle Support account? Click to get started

My Oracle Support provides customers with access to over a
Million Knowledge Articles and hundreds of Community platforms