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

["Canek Peláez Valdés" <caneko@gmail.com>]

On Sat, Sep 7, 2013 at 2:30 PM, Alexander Kapshuk
<alexander.kapshuk@gmail.com> wrote:
> On 09/07/2013 10:25 PM, Canek Peláez Valdés wrote:
>> On Sat, Sep 7, 2013 at 1:53 PM, Alexander Kapshuk
>> <alexander.kapshuk@gmail.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@gmail.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@gmail.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.
> 'mount /boot' fails:
> box0 ~ # mount /boot
> mount: wrong fs type, bad option, bad superblock on /dev/sda1,
>        missing codepage or helper program, or other error
>        In some cases useful info is found in syslog - try
>        dmesg | tail or so
>
> No, I do not use 'initfamfs'.
>
> What do you suggest doing?

Mounting it by hand:

mount -t ext2 /dev/sda1 /boot

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