[CentOS] Help! Help ! i done centos upgrade

m.roth at 5-cent.us m.roth at 5-cent.us
Tue Sep 14 09:39:10 EDT 2010

Theo Band wrote:
>  On 09/13/10 17:48, Ernatalo su Gmail wrote:
>>   i know that this is a good thing, but i've only 1 partition.
>> /boot and /root are in the same partition that i convert from ext3 ti
>> ext4.
>> everything works fine until this morning. I "rebooted" the server many
>> time from the "convertion"
>> but i had never upgrade the Centos before today.
>> with the update the trouble begun!
>> from Installation DVD i can see the /dev/sbd1/ (hd0,0) and with fdisk -l
>> i can see that it's an ext4 partition.
> Nothing to worry if you can still mount the disk while booting from the
> DVD. From the grub shell you can also issue a find command (find
> /boot/grub/grub.conf). Perhaps the disk is mixed up and it is now hd1
> and hd0 is you external drive?
> (hd1,0)/boot/grub/grub.conf
> If you start typing "(hd" and then use command completion, you will see
> which drives are seen by grub like hd0 or hd1 etc, and what partitions
> exist).
> root(hd1)
> configfile /boot/grub/grub.conf
> will get you back to the boot menu. (It's all from my head, so mind some
> typos)

What he said. Also, note that filename completion is enabled in the grub
shell, so if you type
root (hd0,0)
then try
kernel /vm<tab>
and don't get anything, try
root (hd0,1)
or 2, or
root (hd1,0)
etc, until you get a completion. At that point, you'll know what your root
disk is (hd0, or 1, or whatever). Once you boot up and have a running
system again, run
$ grub-install /dev/<whateveryour/bootdrive is), like
$grub-install /dev/sda

Quirk: regardless of what it is, /boot/grub/grub.conf seems to see the
physical drive /boot is on as (hd0)... and don't confuse, say, /dev/sda1
with grub's (hd0,1): two different nomenclatures.


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