Re: [gentoo-user] re: can't find /boot/grub/grub.conf after kernel upgrade [3.10.7]

[Canek Peláez Valdés]

On Sat, Sep 7, 2013 at 1:53 PM, Alexander Kapshuk
<alexander.kapshuk@×××××.com> wrote:
> On 09/07/2013 09:35 PM, Canek Peláez Valdés wrote:
>> On Sat, Sep 7, 2013 at 1:24 PM, Alexander Kapshuk
>> <alexander.kapshuk@×××××.com> wrote:
>>> On 09/07/2013 09:11 PM, Canek Peláez Valdés wrote:
>>>> On Sat, Sep 7, 2013 at 1:06 PM, Alexander Kapshuk
>>>> <alexander.kapshuk@×××××.com> wrote:
>>>>> Howdy,
>>>>>
>>>>> Just compiled the new kernel [3.10.7], was about to edit my
>>>>> /boot/grub/grub.conf, and found it missing:
>>>>> box0 boot # pwd
>>>>> /boot
>>>>> box0 boot # ls -a
>>>>> .  ..  kernel-3.10.7-gentoo  kernel-3.8.13-gentoo
>>>>>
>>>>> What did I miss?
>>>> Do you have /boot in a separated partition? Did you mounted it?
>>>>
>>>> Nothing should touch /boot, AFAIK.
>>>>
>>>> Regards.
>>> I do have '/boot' on a separate partition. If I understand it correctly,
>>> '/boot' gets mounted every time at system start-up, based on
>>> '/etc/fstab', does it not?
>> By the contents of your fstab, it should...
>>
>>> box0 boot # cat /etc/fstab
>>> <snip>
>>> /dev/sda1        /boot        ext2        default,noatime    0 2
>>> /dev/sda2        none        swap        sw        0 0
>>> /dev/sda3        /        ext4        noatime        0 1
>>> /dev/sda5        /home        ext4        noatime            0 2
>>> /dev/cdrom        /mnt/cdrom    auto        noauto,ro    0 0
>>>
>>>
>>> box0 boot # mount|grep /dev/sda
>>> /dev/sda3 on / type ext4 (rw,noatime,data=ordered)
>>> /dev/sda5 on /home type ext4 (rw,noatime)
>> ,,,however mount says up there that it's not mounted.
>>
>>> box0 boot # fdisk -l /dev/sda
>>>
>>> Disk /dev/sda: 250.1 GB, 250059350016 bytes, 488397168 sectors
>>> Units = sectors of 1 * 512 = 512 bytes
>>> Sector size (logical/physical): 512 bytes / 512 bytes
>>> I/O size (minimum/optimal): 512 bytes / 512 bytes
>>> Disk identifier: 0x00000000
>>>
>>>    Device Boot      Start         End      Blocks   Id  System
>>> /dev/sda1   *        2048       67583       32768   83  Linux
>>> /dev/sda2           67584     1116159      524288   82  Linux swap / Solaris
>>> /dev/sda3         1116160    43059199    20971520   83  Linux
>>> /dev/sda4        43059200   488397167   222668984    5  Extended
>>> /dev/sda5        43061248   488397167   222667960   83  Linux
>> For some reason your /boot partition didn't get mounted. See the boot
>> logs, and try to mounting by hand. Perhaps the fsck failed or it needs
>> manual intervention.
>>
>> Regards.
> Based on the 'dmesg' output below, EXT2-fs attempted to mount the '/'
> partition instead of the '/boot' one.
>
> box0 ~ # dmesg|grep 'EXT.*fs'
> [    2.444214] EXT2-fs (sda3): error: couldn't mount because of
> unsupported optional features (240)
> [    2.444736] EXT4-fs (sda3): couldn't mount as ext3 due to feature
> incompatibilities
> [    2.481412] EXT4-fs (sda3): mounted filesystem with ordered data
> mode. Opts: (null)
> [    9.448819] EXT4-fs (sda3): re-mounted. Opts: (null)
> [    9.731383] EXT4-fs (sda5): mounted filesystem with ordered data
> mode. Opts: (null)
>
> Would that suggest a corrupted /boot/grub/grub.conf file?

Not necessarily. Can you manually mount /boot and see the contents of
/boot/grub/grub.conf.

> How did the system boot then?

If grub can see the boot partition (and is correctly configured and
installed on the MBR), it can mount the root system without problems
regardless of fstab. Do you use an initramfs?

Regards.
-- 
Canek Peláez Valdés
Posgrado en Ciencia e Ingeniería de la Computación
Universidad Nacional Autónoma de México