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I am migrating a xen guest. It is running a CentOS 4. I am using the same steps that have worked in the past for our RHEL5 and RHEL6 based systems but for some reason, I'm getting errors.

Here are the steps in brief:

  1. On the guest, install a non-xen kernel and the kernel's devel package.
  2. Turn off database and other services that may cause data inconsistencies
  3. Using VMWare vCenter Converter, migrate data to VMWare
  4. Boot into rescue mode using CentOS 4.8 CD disc 1
  5. Change root to the OS' root mount that rescue mode creates: chroot /mnt/sysimage
  6. Modify /etc/grub/grub.conf so that the non-xen stanza is default
  7. Remove non-xen modules from config: sed -i.pre-vmware '/xen/d' /etc/modprobe.conf
  8. Check /etc/inittab and remove co runlevel and make sure we have lines for other runlevels
  9. Double check /etc/inittab to make sure the Converter configured it correctly
  10. Re-install grub: grub-install --recheck /dev/sda
  11. Finally, recreate init ram disk: mkinitrd -v -f /boot/initr<kernel version>.img <kernel version>

This is what I get when I reboot now:

Kernel panic

Can anyone help? Or provide some some troubleshooting tips? TIA.

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up vote 3 down vote accepted

There is a Red Hat KBase article discussing this issue and a solution. Essentially it looks like you do not have the right storage drivers for your disks. Be sure to include the scsi drivers when you make your initrd image:

# mkinitrd -f -v --with=scsi_mod --with=sd_mod --with=mptbase --with=mptscsi --with=mptspi --with=mptsas --with=mptscsih /boot/initrd-<version>.ELsmp.img <version>.ELsmp
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That did it! I added scsi_mod and sd_mod before but that wasn't sufficient apparently. Thanks! – Belmin Fernandez Dec 12 '12 at 14:56

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