[CentOS] Any alternative to Single User Mode

Mon Jun 15 04:48:23 UTC 2015
Animesh Pandey <animeshpandey.etno at gmail.com>

On Mon, Jun 15, 2015 at 12:33 AM, jd1008 <jd1008 at gmail.com> wrote:

>
>
> On 06/14/2015 10:27 PM, Animesh Pandey wrote:
>
>> On Sun, Jun 14, 2015 at 10:51 PM, jd1008 <jd1008 at gmail.com> wrote:
>>
>>
>>> On 06/14/2015 08:02 PM, Animesh Pandey wrote:
>>>
>>>  On Sun, Jun 14, 2015 at 9:47 PM, jd1008 <jd1008 at gmail.com> wrote:
>>>>
>>>>
>>>>  On 06/14/2015 07:36 PM, Animesh Pandey wrote:
>>>>>
>>>>>   On Sun, Jun 14, 2015 at 9:06 PM, jd1008 <jd1008 at gmail.com> wrote:
>>>>>
>>>>>>
>>>>>>   On 06/14/2015 06:47 PM, Animesh Pandey wrote:
>>>>>>
>>>>>>>    I actually opened the Virtual Disk Image (.vdi) on
>>>>>>>
>>>>>>>  http://www.vmxray.com/
>>>>>>>> .
>>>>>>>> I could see that despite my disk being of 100GB only ~65GB was being
>>>>>>>> shown.
>>>>>>>> All the stuff related ot the local user was not visible at all.
>>>>>>>> After I restarted my VM, the OS gets stuck here (
>>>>>>>> http://i.stack.imgur.com/KVYxV.png). Even after trying the single
>>>>>>>> user
>>>>>>>> login it was stuck there. But the emergency mode worked alright.
>>>>>>>>
>>>>>>>> On Sun, Jun 14, 2015 at 8:37 PM, jd1008 <jd1008 at gmail.com> wrote:
>>>>>>>>
>>>>>>>>
>>>>>>>>    On 06/14/2015 06:28 PM, Animesh Pandey wrote:
>>>>>>>>
>>>>>>>>      Hi,
>>>>>>>>>
>>>>>>>>>   I am working on Centos6.6 on a VirtualBox on Windows Host. Today
>>>>>>>>> I
>>>>>>>>>
>>>>>>>>>> started
>>>>>>>>>> to have booting issues in the OS. It won't get past the loading
>>>>>>>>>> screen.
>>>>>>>>>> I
>>>>>>>>>> checked and found that the files related to the user "cloudera" on
>>>>>>>>>> the
>>>>>>>>>> system were not accessible. Only the files related to root were
>>>>>>>>>> accessible.
>>>>>>>>>> This is why I was am not able to do a single user login but an
>>>>>>>>>> emergency
>>>>>>>>>> login was possible. This is just a guess.
>>>>>>>>>> This all happened due to some update in the Virtual Machine that I
>>>>>>>>>> use
>>>>>>>>>> to
>>>>>>>>>> run CentOS.
>>>>>>>>>>
>>>>>>>>>> Is there any workaround for this issue?
>>>>>>>>>>
>>>>>>>>>> Thanks and regards,
>>>>>>>>>> Animesh Pandey
>>>>>>>>>>
>>>>>>>>>>     I wish you could provide more info.
>>>>>>>>>>
>>>>>>>>>>   How can you determine that inaccessibility to a user's
>>>>>>>>>>
>>>>>>>>> files will prevent centos from taking you all the way to
>>>>>>>>> the login (or welcome) screen?
>>>>>>>>>
>>>>>>>>> I think something else is going on and my guess is that
>>>>>>>>> the centos files themselves have been corruped.
>>>>>>>>> Can you re-install centos ?
>>>>>>>>>
>>>>>>>>>    Please do not top-post.
>>>>>>>>>
>>>>>>>>>  I am having trouble following your terminology.
>>>>>>>>
>>>>>>> Emergency model?
>>>>>>> On my centos installation, there is no "Emergency ...."
>>>>>>> to select from the list of kernels to boot.
>>>>>>>
>>>>>>> Also, when you say "worked alright" do you
>>>>>>> mean that you were able to access what you thought
>>>>>>> was missing?
>>>>>>> Can you go to full multiuser?
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>    Sorry for top posting.
>>>>>>>
>>>>>>>  Let me give you a clearer idea.
>>>>>>
>>>>>> 1. My regular boot freezes after loading is completed.
>>>>>> 2. I read on the internet that sometimes due to an update in
>>>>>> VirtualBox,
>>>>>> this error might occur. To rectify it, I must re-install VirtualBox's
>>>>>> Guest
>>>>>> Additions. For this, I require booting in a Single User Mode.
>>>>>> 3. For that, I followed the correct steps as given here (
>>>>>>
>>>>>>
>>>>>>
>>>>>> https://www.centos.org/docs/5/html/Installation_Guide-en-US/s1-rescuemode-booting-single.html
>>>>>> ).
>>>>>> But still the system froze on that same point.
>>>>>> 4. Then I read about an Emergency mode which is even lower level to
>>>>>> that
>>>>>> of
>>>>>> Single User mode. I was able to log in and see the files that I
>>>>>> created/modified as root. I could not see any file/folder that related
>>>>>> the
>>>>>> local user "cloudera" on which I used to work. This is where I thought
>>>>>> of
>>>>>> seeing the contents of the Image using vmxray.com and found that a
>>>>>> large
>>>>>> part of the dick is not visible. This part contains that files related
>>>>>> to
>>>>>> "cloudera". I felt as if any information related to "cloudera" user
>>>>>> has
>>>>>> been lost.
>>>>>>
>>>>>> I basically need to access files that I made as "cloudera" on CENTOS
>>>>>> and
>>>>>> if
>>>>>> possible re-install the Guest Additions that ma solve this issue. But
>>>>>> for
>>>>>> this I need to be able to boot as a Single User.
>>>>>>
>>>>>>   I assume you are using a virtual drive, which is a file on the host
>>>>>>
>>>>> machine (You said windows??? ).
>>>>> If you can somehow use a tool to dump that disk image to
>>>>> a real hard drive (for example using dd ), and connect
>>>>> the hard drive a a working linux computer to run fsck on it
>>>>> to see what it will find.
>>>>> I assume you have no backup of your drive???
>>>>>
>>>>>
>>>>> _______________________________________________
>>>>> CentOS mailing list
>>>>> CentOS at centos.org
>>>>> http://lists.centos.org/mailman/listinfo/centos
>>>>>
>>>>>   Yes it is windows. By dumping a disk image do you mean a VDI
>>>>> (VirtualBox
>>>>>
>>>> Disk Image). These are files that are used by VirtualBox for booting. I
>>>> have a copy of that as well. Can Gparted be used for connecting that
>>>> VDI?
>>>>
>>>>   You will more than likely need a conversion tool to convert a vdi
>>>>
>>> image to a normal HD image. I do not know of such a tool.
>>>
>>> Another possibility is to create another VM, install your linux on it
>>> with it's own separate disk, but add you bad vdi disk
>>> as a second drive. Once booted, use linux to fsck the second
>>> drive.
>>> Again, be sure you have a copy it before you connect it to this
>>> new VM.
>>>
>>>
>>> _______________________________________________
>>> CentOS mailing list
>>> CentOS at centos.org
>>> http://lists.centos.org/mailman/listinfo/centos
>>>
>>>  I did exactly as you said. I used Gparted to create a secondary drive. I
>> can do "/dev/" to see the four partitions that my original VM had. How do
>> I
>> go about it now?
>>
>
> So, the drive (you want to fix) is visible in the new vm.
> Good.
> be sure it is unmounted.
> As root, run fsck /dev/sd?
> You supply the value of ?
> Is it b or c ...?
>
> fsck could end up deleting files or even truncating them
> to shorter lengths if blocks that belong to those
> files are no longer referenced in the file's inode.
>
> Good luck
>
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>

This is how it looks as of now:
When running "fdisk -l", I get this <http://i.imgur.com/UFp7DOw.png>.

"fsck" results in this <http://i.imgur.com/3TnDMEq.png>