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-   -   Boot error: "No bootable device" (https://www.linuxquestions.org/questions/linux-newbie-8/boot-error-no-bootable-device-4175449021/)

yashfire007 02-07-2013 09:14 AM

Boot error: "No bootable device"
 

When used to run the fdisk -l cmd it is showing as the error
"/dev/sda has no valid partition". And meanwhile trying to edit any file which was created by showing the error: warning the file is read only file. So that i have rebooted the machine. It is not booting to any O.s Because i installed winxp and centO.S.(dual boot)
It is showing in the black screen
"No bootable device -- insert boot disk and press any key..
Please suggest otherwise i have to format the machine..

PTrenholme 02-07-2013 10:09 AM

Do you have access to any Live CD or USB from which you can boot your system? If you can, you could use the tools on the Live CD to investigate your problem.

The "no valid partition" message is sometimes caused by a GUID partition not working with software (like fdisk) that don't support that partitioning scheme. The newer releases of fdisk will usually warn you, and show something.

The "No bootable device" message is a Windows boot error message, so your "dual boot" system was attempting to boot directly to XP, which won't work unless the XP is on the first partition of the drive. Your problem may be as simple as XP replacing the MBR of the drive with it's own (primitive) boot loader, which can't read non-windows partitions. If that's the case you could reinstall a modern boot loader from the Live boot system - after you get one, of course.

TobiSGD 02-07-2013 11:18 AM

Quote:

Originally Posted by PTrenholme (Post 4886326)
The "No bootable device" message is a Windows boot error message, so your "dual boot" system was attempting to boot directly to XP, which won't work unless the XP is on the first partition of the drive. Your problem may be as simple as XP replacing the MBR of the drive with it's own (primitive) boot loader, which can't read non-windows partitions. If that's the case you could reinstall a modern boot loader from the Live boot system - after you get one, of course.

Actually, this message is a message directly from the BIOS, issued when it is not able to find a bootloader. So the first thing to test if your disk is shown in the BIOS.
If so, please boot from a live-medium and post the complete output of
Code:

fdisk -l
launched as root. If no valid partition table is found and no bootloader it seems that your MBR (and possibly more of the disk) has been overwritten. Have you done any system critical tasks before the error occured?

yashfire007 02-07-2013 10:22 PM

Yes i tried to write zero sector in my usb.
Instead of giving #shred /dev/sdb , wrongly i gave #shred /dev/sda. But within two seconds i cancelled the process..

chrism01 02-07-2013 10:32 PM

Assuming that XP was the first OS on the system and installed on /dev/sda, I believe the cmd would be fixmbr, but I think you'd need a MS rescue disk like this http://sathyasays.com/2008/10/29/how...ows-dual-boot/

TobiSGD 02-07-2013 11:30 PM

I am not quite sure how fast the shred command works, but if it goes up to the disks maximum speed 2 seconds is quite a lot.
Try Testdisk from a live medium to restore the partition table, after that you can restore the bootloader and should at least be able to boot your Linux system, assuming that Windows was installed on the first partition.

It may be possible, although unlikely, that you will be able to recover the OS on the first partition, but I doubt it. But you should be able to recover most of your data using Photorec.

fortran 02-08-2013 06:01 AM

Are you not able to boot any of operating system? Are you using 64 bit centOS? Please comment.
If you can't boot you can't go in recovery mode.
Are you getting same error always or you get following error too
Kernel panic - not syncing: VFS: Unable to mount root fs on unknow-block(0,0)
Try to boot centOS using live dvd and fix the partitions.
or if you do not have live dvd make bootable pendrive using "Universal Netboot Installer"
If you have done evrything and you are going to reinstall the OS please once try following solution.
Remove your RAM (If two, both), clean it with soft cloth and put it again.

TobiSGD 02-08-2013 06:03 AM

Removing and cleaning the RAM will not magically restore an overwritten file-system.

colucix 02-08-2013 07:04 AM

Please use a descriptive title for your thread excluding words like 'urgent' or 'help'. Using a proper title makes it easier for members to help you. This thread has been reported for title modification. Please do not add replies that address the thread title.

TB0ne 02-08-2013 09:13 AM

Quote:

Originally Posted by TobiSGD (Post 4886933)
Removing and cleaning the RAM will not magically restore an overwritten file-system.

Agreed...that's kind of like saying "If your car won't start, try cleaning the windshield"....

bloodstreetboy 02-08-2013 09:31 AM

Quote:

Originally Posted by TB0ne (Post 4887050)
Agreed...that's kind of like saying "If your car won't start, try cleaning the windshield"....

That is d difference between car & software, you can never know which technique can it fix?
By the way this is the common solution of given error(no boot device found) if you dont believe,just google it.

TB0ne 02-08-2013 04:29 PM

Quote:

Originally Posted by bloodstreetboy (Post 4887067)
That is d difference between car & software, you can never know which technique can it fix?

You may not know EXACTLY what will fix software, especially when you don't understand it, but there are lots of things that you DO know won't work (or won't make a difference at all). Cleaning the RAM pins is one of them. How, exactly, would removing a piece of lint on a RAM chip fix a corrupted MBR? Or make a hard drive work? The only thing it MAY affect is a memory error...and that usually points to BAD memory, rather than a dirty pin.
And please, spell out your words.
Quote:

By the way this is the common solution of given error(no boot device found) if you dont believe,just google it.
I don't believe it, and I did Google it...and not surprisingly, it didn't turn up anything. Why don't you post a few links that have some good information about it???

TobiSGD 02-09-2013 07:41 AM

The OP has accidentally overwritten parts of his harddisk. Cleaning, removing or even exchanging the RAM will not restore those overwritten parts, simple as that. No Google needed for that.

PTrenholme 02-09-2013 02:09 PM

Yes, the OP explained how the MBR and partition table was overwritten.

If the system can be booted from some live media, then the rescue option of the parted command might be able to help. It depends on how much of the hard drive was shredded before the error was noticed.

Since the command used (shred /dev/sda) defaulted to three over-write passes of random data, and it was aborted after two seconds, it's likely that most of the data on the drive is still intact but, clearly, not all.

Perhaps the more robust recovery would be to follow the advice of the moderator in post #6, above.

bloodstreetboy 02-10-2013 02:14 AM

@TB0ne
Some one is sharing these types of solutions here and other is proving correct it. It is ok for you, These posts don't bother you. you don't say anything here.
http://www.linuxquestions.org/questi...-a-4175449295/
but if some one gives a solution to remove its hardware & put it again, it is very dangerous solution for you.


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