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While much of the work I do is focused around Windows, I also manage a number of Linux servers as well (primarily CentOS). Recently at my place of employment we underwent a fairly major project, virtualizing 90% of our systems. In the process of doing so we ran into a number of different problems, one of which was an issue where ESXi was not properly installing the disk drivers for the created VMs.

In my search to find a solution to this, I came across a great post here which got me 80% of the way there however, there were still a number of other things that needed to be updated/changed to get things to work 100%. The post was written for ESXi 4.0 and I was performing these migrations using ESXi 4.1 and 5.0, so that may be have been the reason for the differences.

In any case, the step-by-step instructions for what needed to be done to get things working is below:

#Boot to Linux Rescue
Mount CentOS disc 1 and boot from disc, then enter Linux Rescue

##Start network interfaces?
No

##Allow rescue environment to find Linux installation
Choose “Continue”

##Chroot to the mounted image
chroot /mnt/sysimage

#Configure SCSI driver that will work
vi /etc/modprobe.conf

alias scsi_hostadapter mptscsih
(Delete any other adapters listed)

##Save modified modprobe.conf
Esc > :wq

#Load SCSI device

##Check CentOS kernel version
cat /etc/grub.conf

vmlinuz-2.6.18-308.8.2.e15

##Load the SCSI device
mkinitrd -v -f –preload mptbase –with=mptbase /boot/initrd-2.6.18-308.8.2.el5.img 2.6.18-308.8.2.el5

#GRUB

##Check grub.conf file
vi /boot/grub/grub.conf

##Ensure kernel file looks similar to below
kernel /vmlinuz-2.6.18-308.8.2.el5 ro root=/dev/sda3

##Exit the file (without changes most likely)
Esc > :q

##Open grub
grub

## Install mkinitrd package into the GRUB partition
grub> root (hd0,0)
(stuff snipped)
grub> setup (hd0)
(more stuff snipped)

##Exit GRUB
quit

#FSTAB

##Check fstab file to ensure swap to tell Linux where the swap file lives
vi /etc/fstab

##(something similar to below needs to be there)
/dev/VolGroup00/LogVol01 swap swap defaults 0 0

##Exit the file (without changes most likely)
Esc > :q

#Reboot system
exit
exit