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dual-boot interview questions

Top dual-boot frequently asked interview questions


How can I dual-boot Windows 10 and Ubuntu on a UEFI HP notebook?

I've got an HP Pavilion Touchsmart notebook that came with Windows 8. I've upgraded to 8.1, and now I want to dual-boot an Ubuntu distribution with Windows 10. When dual-booting with Windows 8.1, the Windows Boot Manager always took priority, even after installing GRUB. What do I need to do to get GRUB to be the default bootloader instead of Windows Boot Manager?


Source: (StackOverflow)

Where to install bootloader when installing Ubuntu as secondary OS?

I'm trying to install Ubuntu as secondary OS on my laptop. I have Windows 8 already installed on my laptop.

Now, I know how to run Ubuntu from USB drive, I created addition partition and formatted it to EXT4.

So I'm ready to install.

Now, 'Device for boot loader installation:' displays:

/dev/sta ATA HITACHI (750 GB)
/dev/sta1 Windows 8 (loader)
/dev/sta2
/dev/sta5
/dev/sta6 Ubuntu 12.04 (12.04)
/dev/stb

I tries choosing Ubuntu 12.04 partition but it doesn't even let me to pick which OS to install and goes straight to Windows 8.

Which partition I must choose to be able to pick which OS to boot from? Preferably, set up so Windows 8 will be at first place, and Ubuntu on second.

Any ideas? I don't want to mess up anything if I pick something wrong.


Source: (StackOverflow)

How to reboot into Windows from Ubuntu?

I'm looking for a way to reboot into Windows from Ubuntu on a 10.10/Vista dual boot system. The specific use case is that I would like to be able to ssh into my running Ubuntu instance and issue a command that will initiate a reboot directly into Windows.

I found a promising blog post, but the script that it suggests isn't working:

#!/bin/bash

WINDOWS_ENTRY=`grep menuentry /boot/grub/grub.cfg  | grep --line-number Windows`
MENU_NUMBER=$(( `echo $WINDOWS_ENTRY | sed -e "s/:.*//"` - 1 ))
sudo grub-reboot $MENU_NUMBER
sudo reboot

man grub-reboot isn't much help, but it seems to be leading me in the right direction:

set the default boot entry for GRUB, for the next boot only

WINDOWS_ENTRY=`grep menuentry /boot/grub/grub.cfg  | grep --line-number Windows`
MENU_NUMBER=$(( `echo $WINDOWS_ENTRY | sed -e "s/:.*//"` - 1 ))
echo $MENU_NUMBER

This returns the expected value, but on reboot the first menu entry is still highlighted. Any ideas why this isn't working or suggestions for other solutions?


Source: (StackOverflow)

How to install Windows 7 after Ubuntu and dual boot? [duplicate]

This question already has an answer here:

I just installed Ubuntu, a full install removing the prior OS. I was forced to remove Windows 7 from my HP dv6 because of the max four partitions already being there. I didn't lose anything, all backed up. However, now I am looking to create another partition and install Windows 7 on it.

Do I also need some sort of boot loader that lets me choose which to boot?


Source: (StackOverflow)

Grub does not show a Windows 8 option after dual boot

So, I've successfully dual-booted my Windows 8 machine with Ubuntu 12.04 . However, I still don't have a convenient method of choosing what OS to load at boot time.

After installing Ubuntu, my computer still loads Windows 8 directly. I then added grubx64.efi to the white list of my boot loader. But after that, my machine loads Ubuntu directly without even a shadow of GRUB showing up!

I used boot-repair and I got this paste.ubuntu URL: paste.ubuntu.com/1326074. After running boot-repair (and re-white listing the grubx64.efi file), GRUB now shows up but without any Windows 8 option!

Lastly, I ran sudo fdisk -l and it gave me this:

WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted.


Disk /dev/sda: 750.2 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders, total 1465149168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x6396389f

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1  1465149167   732574583+  ee  GPT
Partition 1 does not start on physical sector boundary.

I'm guessing my problem has something to do with the warning from fdisk above but I don't know what to do with it. How do I proceed now?

Edit

My etc/default/grub is as follows:

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
#GRUB_HIDDEN_TIMEOUT=0
GRUB_HIDDEN_TIMEOUT_QUIET=true
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

Also, just for the record, this is what I followed in installing my dual-boot. The tutorial (which uses, 11.10, I must note), doesn't mention anything about this problem. Is there anything there I shouldn't have done?


Source: (StackOverflow)

Hide GRUB2 menu UNLESS you hold down Shift key: how to make this happen?

I have a Ubuntu - Windows 7 dual-boot set-up, and I would like to have it that my laptop would boot up Windows 7 unless I press down the Shift key right after boot and bring up the Grub2 menu from which I can choose Ubuntu.

I researched on Grub2 and options for etc/default/grub and I have tried playing around with combinations with the GRUB_TIMEOUT and GRUB_HIDDEN_TIMEOUT values, but to no avail. I tried setting the GRUB_HIDDEN_TIMEOUT higher than the GRUB_TIMEOUT thinking that both countdown start simultaneously, but no - GRUB_TIMEOUT only starts after the other is done.

Is this behavior achievable?

If so, how?


Source: (StackOverflow)

How to set Windows bootloader as default bootloader?

I have a Win 7/11.10 dual boot system with Grub 2 as the default bootloader. However, I want to make Windows bootloader the default bootloader (grub 'dos' like interface scrares the hell out of my sister) so when I start the PC I will have the following boot options: 1. Windows 7 2. Ubuntu

NB: A process to reverse this operation so Grub can be the default bootloader again will also be appreciated


Source: (StackOverflow)

Should I choose exFat or NTFS for a "shared" partition in a dual-boot system?

I have a new laptop which I am setting up as dual boot Windows/Linux.

I would like to access files from both Ubuntu and Windows 7.

Should I create a separate NTFS partition?


Source: (StackOverflow)

Windows 8 removes Grub as default boot manager

I have a Sony VAIO S series with Windows 8 preinstalled, and I installed Ubuntu 12.10 on a new partition. When the PC boots Grub is display, and I can choose between Windows 8 (didn't worked at the beginning, had to change Grub settings) and Ubuntu 12.10. When I select Ubuntu 12.10 everything is OK, but when I use Windows 8, and I restart Grub isn't displayed anymore (Windows 8 boots immediately).

I booted a Ubuntu 12.10 LiveUSB, used efibootmgr, and found out that Windows 8 (each time it boots) changes EFI default bootloader from Grub to Windows Boot Manager.

How do I change this in Windows 8? I read something about bcdedit, but it does not work or I don't know how to use it...


Source: (StackOverflow)

A common /home partition for multiple Linux distributions

I have an Ubuntu installed in one partition, Debian on the other and now I am planning to install backtrack and SUSE also. Debian mounts a separate partition as its home mount point, whereas Ubuntu contains its own home folder in its file system.

Now, I want my home partition to be shared by all other distros I have currently or might have on the future.

How can I do this?

P.S. I have same username & nicknames on all the distros


Source: (StackOverflow)

My main username is not in the sudoers file

I was trying to install some software/edit files with my main username(not root) But I got this error [X] is not in the sudoers file. This incident will be reported.
I tried to edit the /etc/sudoers file by using sudo and su username but I got the same error!

How I'm supposed to add my username tosudoers file while I cant access it anyway?
I also tried to follow this guide here.

is the guide says, when booting 2 Operating systems(that's my case), then selecting Ubuntu, a menu will let you choose to start normally/open recovery mode/etc, but it's not happening for me, even if I hold shift no menu will pop up.

I installed Ubuntu by using Wubi and my Ubuntu version:12.04 LTS.


Source: (StackOverflow)

Windows 10 upgrade lead into grub rescue

I was dual-booting Windows 7 and Linux Ubuntu on my desktop, and today is the day they gave out free Windows 10 upgrades. How exciting! I got the update, and it was installing, and I left to go take a 30 minute nap. However, when I came back to my computer, it led me to the grub rescue prompt.

error: no such partition.
Entering rescue mode...
grub rescue>

I get the following when I type ls:

grub rescue> ls
(hd0) (hd0,msdos5) (hd0,msdos3) (hd0,msdos2) (hd0,msdos1)

After a quick look through of people who encountered the grub rescue prompt, I typed set and got the following

grub rescue> set
cmdpath=(hd0)
prefix=(hd0,msdos6)/boot/grub
root=hd0,msdos6

I was still kind of lost after finding that certain commands like normal didn't work, and then I found a video tutorial where you boot from a Linux image cd and run some commands on the terminal. Luckily, I had my CD with me, and booted from there. When I typed sudo fdisk -l into the terminal however, this is what I got:

ubuntu@ubuntu:~$ sudo fdisk -l

Disk /dev/sda: 1000.2 GB, 1000204886016 bytes
255 heads, 63 sectors/track, 121601 cylinders, total 1953525168 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: 0xc03ede74

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048      206847      102400    7  HPFS/NTFS/exFAT
/dev/sda2          206848  1547022335   773407744    7  HPFS/NTFS/exFAT
/dev/sda3      1547022336  1547943935      460800   27  Hidden NTFS WinRE
/dev/sda4      1547945982  1953521663   202787841    f  W95 Ext'd (LBA)
/dev/sda5      1915731968  1953521663    18894848    7  HPFS/NTFS/exFAT

Says here none of my devices has the Linux system in them! And I couldn't follow the video tutorial any more than that...

I teased my brain a little and determined that sda2 contained my Windows system (since I remember my C: drive has around 700-ish GB of space). After thinking a little bit more, I remember assigning around 200-ish GB of my hard disk space to something that's Ubuntu related when installing Ubuntu. I don't exactly remember which, but I think it was basically Ubuntu "hard disk space", and it didn't have any boot files in them. I assigned two other things for linux, but they were very small in size (not breaking the 1 GB mark yet).

So, can anyone here help me out get my upgrade back on track? I won't mind if I end up having to completely remove the partitions that have Linux in them.


Source: (StackOverflow)

Automatically mount NTFS drive when I login

I use Ubuntu 11.10 and Windows7 dual boot with Ubuntu as my primary OS.

Every time I need to access a document I need to mount the respective drive, though this is not at all tiresome, still, is there any way that drives becomes automatically mounted when I login?


Source: (StackOverflow)

Is Ubuntu destroying my internal HDD?

I have an Inspiron 3521 that came pre-installed with Windows 8.1. I decided to dual-boot Windows and Ubuntu, and it was working good. But, when using Ubuntu, I heard a lot of noise from my laptop while on using Windows, it was almost silent. Also, after about 2-3 weeks of using Ubuntu, I was unable to use Windows as it had become very slow. Now I am getting my HDD replaced as it is failing. So, is installing Ubuntu and using it destroying my HDD? Because before installing it, Windows was running well but after it, it has become almost unusable. So, should I install Ubuntu on my new disk or should I refrain from it. Please help because I like Ubuntu more than Windows, but I can't risk buying new HDDs over and over again. Also, completely removing Windows is not a choice.

Please let me know if I should install Ubuntu alongside?

Output of : smartctl -a /dev/sda :

=== START OF INFORMATION SECTION ===
Device Model:     ST500LT012-1DG142
Serial Number:    W3P8Y9MR
LU WWN Device Id: 5 000c50 07c643db0
Firmware Version: 0001SDM1
User Capacity:    500,107,862,016 bytes [500 GB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Rotation Rate:    5400 rpm
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   ATA8-ACS T13/1699-D revision 4
SATA Version is:  SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is:    Tue Feb 17 15:58:15 2015 IST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED

General SMART Values:
Offline data collection status:  (0x82) Offline data collection activity
                    was completed without error.
                    Auto Offline Data Collection: Enabled.
Self-test execution status:      (   0) The previous self-test routine completed
                    without error or no self-test has ever 
                    been run.
Total time to complete Offline 
data collection:        (    0) seconds.
Offline data collection
capabilities:            (0x7b) SMART execute Offline immediate.
                    Auto Offline data collection on/off support.
                    Suspend Offline collection upon new
                    command.
                    Offline surface scan supported.
                    Self-test supported.
                    Conveyance Self-test supported.
                    Selective Self-test supported.
SMART capabilities:            (0x0003) Saves SMART data before entering
                    power-saving mode.
                    Supports SMART auto save timer.
Error logging capability:        (0x01) Error logging supported.
                    General Purpose Logging supported.
Short self-test routine 
recommended polling time:    (   1) minutes.
Extended self-test routine
recommended polling time:    (  97) minutes.
Conveyance self-test routine
recommended polling time:    (   2) minutes.
SCT capabilities:          (0x1035) SCT Status supported.
                    SCT Feature Control supported.
                    SCT Data Table supported.

SMART Attributes Data Structure revision number: 10
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000f   117   080   006    Pre-fail  Always       -       158207928
  3 Spin_Up_Time            0x0003   099   099   000    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0032   100   100   020    Old_age   Always       -       414
  5 Reallocated_Sector_Ct   0x0033   100   100   036    Pre-fail  Always       -       16
  7 Seek_Error_Rate         0x000f   064   060   030    Pre-fail  Always       -       38678857862
  9 Power_On_Hours          0x0032   100   100   000    Old_age   Always       -       772 (87 233 0)
 10 Spin_Retry_Count        0x0013   100   100   097    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   020    Old_age   Always       -       384
184 End-to-End_Error        0x0032   100   100   099    Old_age   Always       -       0
187 Reported_Uncorrect      0x0032   001   001   000    Old_age   Always       -       1465
188 Command_Timeout         0x0032   100   100   000    Old_age   Always       -       0
189 High_Fly_Writes         0x003a   100   100   000    Old_age   Always       -       0
190 Airflow_Temperature_Cel 0x0022   059   052   045    Old_age   Always       -       41 (Min/Max 29/43)
191 G-Sense_Error_Rate      0x0032   100   100   000    Old_age   Always       -       195
192 Power-Off_Retract_Count 0x0032   100   100   000    Old_age   Always       -       14
193 Load_Cycle_Count        0x0032   096   096   000    Old_age   Always       -       8566
194 Temperature_Celsius     0x0022   041   048   000    Old_age   Always       -       41 (0 17 0 0 0)
197 Current_Pending_Sector  0x0012   100   100   000    Old_age   Always       -       8
198 Offline_Uncorrectable   0x0010   100   100   000    Old_age   Offline      -       8
199 UDMA_CRC_Error_Count    0x003e   200   200   000    Old_age   Always       -       0
240 Head_Flying_Hours       0x0000   100   100   000    Old_age   Offline      -       276333900858102
241 Total_LBAs_Written      0x0000   100   253   000    Old_age   Offline      -       2960885917
242 Total_LBAs_Read         0x0000   100   253   000    Old_age   Offline      -       5374462826
254 Free_Fall_Sensor        0x0032   100   100   000    Old_age   Always       -       0

SMART Error Log Version: 1
ATA Error Count: 2175 (device log contains only the most recent five errors)
    CR = Command Register [HEX]
    FR = Features Register [HEX]
    SC = Sector Count Register [HEX]
    SN = Sector Number Register [HEX]
    CL = Cylinder Low Register [HEX]
    CH = Cylinder High Register [HEX]
    DH = Device/Head Register [HEX]
    DC = Device Command Register [HEX]
    ER = Error register [HEX]
    ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.

Error 2175 occurred at disk power-on lifetime: 758 hours (31 days + 14 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 20 19 56 00  Error: UNC at LBA = 0x00561920 = 5642528

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 00 ff ff ff 4f 00      00:15:34.369  READ FPDMA QUEUED
  61 00 68 ff ff ff 4f 00      00:15:34.369  WRITE FPDMA QUEUED
  61 00 10 ff ff ff 4f 00      00:15:34.369  WRITE FPDMA QUEUED
  60 00 08 20 19 56 40 00      00:15:34.368  READ FPDMA QUEUED
  60 00 40 ff ff ff 4f 00      00:15:34.368  READ FPDMA QUEUED

Error 2174 occurred at disk power-on lifetime: 758 hours (31 days + 14 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 20 19 56 00  Error: UNC at LBA = 0x00561920 = 5642528

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 08 20 19 56 40 00      00:15:31.814  READ FPDMA QUEUED
  60 00 20 ff ff ff 4f 00      00:15:31.814  READ FPDMA QUEUED
  61 00 08 ff ff ff 4f 00      00:15:31.813  WRITE FPDMA QUEUED
  ea 00 00 00 00 00 a0 00      00:15:31.813  FLUSH CACHE EXT
  27 00 00 00 00 00 e0 00      00:15:31.787  READ NATIVE MAX ADDRESS EXT [OBS-ACS-3]

Error 2173 occurred at disk power-on lifetime: 758 hours (31 days + 14 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 20 19 56 00  Error: WP at LBA = 0x00561920 = 5642528

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  61 00 10 ff ff ff 4f 00      00:15:29.177  WRITE FPDMA QUEUED
  61 00 08 ff ff ff 4f 00      00:15:29.177  WRITE FPDMA QUEUED
  61 00 08 ff ff ff 4f 00      00:15:29.177  WRITE FPDMA QUEUED
  60 00 08 20 19 56 40 00      00:15:29.176  READ FPDMA QUEUED
  60 00 08 ff ff ff 4f 00      00:15:29.176  READ FPDMA QUEUED

Error 2172 occurred at disk power-on lifetime: 758 hours (31 days + 14 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 20 19 56 00  Error: WP at LBA = 0x00561920 = 5642528

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  61 00 08 ff ff ff 4f 00      00:15:26.514  WRITE FPDMA QUEUED
  61 00 18 ff ff ff 4f 00      00:15:26.513  WRITE FPDMA QUEUED
  60 00 08 20 19 56 40 00      00:15:26.513  READ FPDMA QUEUED
  60 00 40 ff ff ff 4f 00      00:15:26.513  READ FPDMA QUEUED
  61 00 08 ff ff ff 4f 00      00:15:26.513  WRITE FPDMA QUEUED

Error 2171 occurred at disk power-on lifetime: 758 hours (31 days + 14 hours)
  When the command that caused the error occurred, the device was active or idle.

  After command completion occurred, registers were:
  ER ST SC SN CL CH DH
  -- -- -- -- -- -- --
  40 51 00 20 19 56 00  Error: UNC at LBA = 0x00561920 = 5642528

  Commands leading to the command that caused the error were:
  CR FR SC SN CL CH DH DC   Powered_Up_Time  Command/Feature_Name
  -- -- -- -- -- -- -- --  ----------------  --------------------
  60 00 40 ff ff ff 4f 00      00:15:18.647  READ FPDMA QUEUED
  60 00 20 ff ff ff 4f 00      00:15:18.641  READ FPDMA QUEUED
  60 00 08 ff ff ff 4f 00      00:15:18.629  READ FPDMA QUEUED
  60 00 20 ff ff ff 4f 00      00:15:18.619  READ FPDMA QUEUED
  60 00 20 ff ff ff 4f 00      00:15:18.607  READ FPDMA QUEUED

SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Short offline       Completed: read failure       90%       760         5642528
# 2  Short offline       Completed: read failure       90%       759         5642528
# 3  Short offline       Completed: read failure       90%       759         5642528
# 4  Short offline       Completed: read failure       90%       758         5642528
# 5  Short offline       Completed: read failure       90%       756         5642528
# 6  Short offline       Completed: read failure       90%       752         5642528
# 7  Extended offline    Completed: read failure       90%       752         5642528
# 8  Short offline       Completed: read failure       90%       752         5642528

SMART Selective self-test log data structure revision number 1
 SPAN  MIN_LBA  MAX_LBA  CURRENT_TEST_STATUS
    1        0        0  Not_testing
    2        0        0  Not_testing
    3        0        0  Not_testing
    4        0        0  Not_testing
    5        0        0  Not_testing
Selective self-test flags (0x0): 
  After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.

Note: The above test is from the old HDD, which I think was destroyed by coincidence while running Ubuntu.

Output of sudo parted --list:

Model: ATA ST500LT012-1DG14 (scsi)
Disk /dev/sda: 500GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt

Number  Start   End    Size    File system     Name                          Flags
 1      1049kB  316MB  315MB   ntfs            Basic data partition          hidden, diag
 2      316MB   419MB  104MB   fat32           EFI system partition          boot
 3      419MB   554MB  134MB                   Microsoft reserved partition  msftres
 4      554MB   237GB  236GB   ntfs            Basic data partition          msftdata
10      237GB   289GB  52.4GB  ext4
 7      289GB   293GB  4096MB  linux-swap(v1)
 8      293GB   314GB  20.5GB  ext4
 9      314GB   342GB  27.9GB  ext4
 5      342GB   395GB  53.7GB  ntfs            Basic data partition          msftdata
 6      395GB   500GB  105GB   ntfs            Basic data partition          msftdata

Source: (StackOverflow)

Grub rescue - error: unknown filesystem

I have a multiboot system set up. The system has three drives. Multiboot is configured with Windows XP, Windows 7, and Ubuntu - all on the first drive. I had a lot of unpartitioned space left on the drive and was reserving it for adding other OSes and for storing files there in the future.

One day I went ahead and downloaded Partition Wizard and created a logical NTFS partition from within Windows 7, still some unpartitioned space left over. Everything worked fine, until I rebooted the computer a few days later.

Now I'm getting:

error: unknown filesystem.  
grub rescue>

First of all I was surprised not to find any kind of help command, by trying:

help, ?, man, --help, -h, bash, cmd, etc.

Now I'm stuck with non-bootable system. I have started researching the issue and finding that people usually recommend to boot to a Live CD and fix the issue from there. Is there a way to fix this issue from within grub rescue without the need for Live CD?

UPDATE

By following the steps from persist commands typed to grub rescue, I was able to boot to initramfs prompt. But not anywhere further than that.

So far from reading the manual on grub rescue, I was able to see my drives and partitions using ls command. For the first hard drive I see the following:
(hd0) (hd0,msdos6) (hd0,msdos5) (hd0,msdos2) (hd0,msdos1)

I now know that (hd0,msdos6) contains Linux on it, since ls (hd0,msdos6)/ lists directories. Others will give "error: unknown filesystem."

UPDATE 2

After the following commands I am now getting to the boot menu and can boot into Windows 7 and Ubuntu, but upon reboot I have to repeat these steps.

ls
ls (hd0,msdos6)/
set root=(hd0,msdos6)
ls /
set prefix=(hd0,msdos6)/boot/grub
insmod /boot/grub/linux.mod
normal

UPDATE 3

Thanks Shashank Singh, with your instructions I have simplified my steps to the following. I have learned from you that I can replace msdos6 with just a 6 and that I can just do insmod normal instead of insmod /boot/grub/linux.mod. Now I just need to figure out how to save this settings from within grub itself, without booting into any OS.

set root=(hd0,6)
set prefix=(hd0,6)/boot/grub
insmod normal
normal

UPDATE 4

Well, it seems like it is a requirement to boot into Linux. After booting into Ubuntu I have performed the following steps described in the manual:

sudo update-grub
sudo grub-install /dev/sda

This did not resolve the issue. I still get the grub rescue prompt. What do I need to do to permanently fix it?

I have also learned that drive numbers as in hd0 need to be translated to drive letters as in /dev/sda for some commands. hd1 would be sdb, hd2 would be sdc, and so on. Partitions listed in grub as (hd0,msdos6) would be translated to /dev/sda6.

UPDATE 5

I could not figure out why the following did not fix grub:

sudo update-grub
sudo grub-install /dev/sda

So I downloaded boot-repair based on an answer from https://help.ubuntu.com/community/Boot-Repair post. That seemed to do the trick after I picked the "Recommended Repair (repairs most frequent problems)" option.


Source: (StackOverflow)