I am having a very strange problem installing CentOS 6 that I've never encountered before. I've followed these same steps thousands of times before, but within the past couple weeks I've had two separate servers that would boot to a grub prompt after a fresh CentOS 6 install. Here are the steps of what I've done:
I download the CentOS 6 net-install ISO to a Windows file-share.
I use the IPMI web interface on my Supermicro server to mount the ISO as a USB virtual CD-ROM.
I then proceed to install CentOS 6 with the default partitioning and default boot loader (installed into the MBR). At this point, everything is normal.
I unmount the virtual CD-ROM and reboot the server to complete the installation. Instead of booting up CentOS, it goes to a GRUB version 0.97 prompt.
I use the grub command
root (hd0,0)to attempt to select the correct disk and then boot into the operating system, but when I type that command I get an
Error 21that the disk does not exist. I also try running
root (hd1,0)thinking that the system labelled the primary drive as /dev/sdb during the installation. No such luck -- I get a
disk read errormessage.
At this point I reboot the server and use the install CD to get into rescue mode. I use rescue mode to inspect /boot/grub/device.map and /boot/grub/grub.conf -- everything is exactly as it should be -- (hd0) is mapped to /dev/sda and /boot/grub/grub.conf points to (hd0,0) for the boot partition. An
fdisk -lcommand confirms that the boot partition is indeed setup on /dev/sda1
For good measure, I ran
grub-install /dev/sdato re-install grub and rebooted the server. After I did that, I was no longer able to get to the grub prompt -- instead my server would just display an
Error 21error message indicating the selected disk does not exist.
I then proceeded to swap out hard drives and use a CentOS 6 net-install ISO hosted on a different mirror, repeated the steps above and got the same issue each time.
Screen capture of my grub.conf, device.map and
fdisk -l from rescue shell: http://pbrd.co/1ijpSke
Screen capture failing to select
(hd0,0) from grub prompt: http://pbrd.co/1ijr33d
I am able to install other operating systems on this server (I installed Ubuntu shortly thereafter without issue), but not CentOS 6.
I'm stumped where to go next. Any ideas?