Minor disk drive issue

[MrGrado]

I have two hard drives in my computer and one has ubuntu 11.04 installed. The other drive doesn't have anything on it that is required as far as I know.

I want to take the hard disk out that isn't being used but when I do ubuntu will not boot up.

[lmarmisa]

I think that your problem will be solved after your reinstall the grub loader in the MBR of your Ubuntu hard drive. Maybe you have to take a look to the BIOS menu in order to define your boot disk too.

First of all, post the result of this command:



sudo fdisk -l

[MrGrado]

thanks for the fast reply.


Disk /dev/sda: 203.9 GB, 203927027200 bytes
255 heads, 63 sectors/track, 24792 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xffffffff

Device Boot Start End Blocks Id System
/dev/sda1 * 1 17847 143355996 7 HPFS/NTFS
/dev/sda2 17848 24792 55785712+ 7 HPFS/NTFS

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


Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xe92cb5b2

Device Boot Start End Blocks Id System
/dev/sdb1 1 243202 1953514583+ ee GPT

Disk /dev/dm-0: 203.9 GB, 203927026176 bytes
255 heads, 63 sectors/track, 24792 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xffffffff

Device Boot Start End Blocks Id System
/dev/dm-0p1 * 1 17847 143355996 7 HPFS/NTFS
/dev/dm-0p2 17848 24792 55785712+ 7 HPFS/NTFS

Disk /dev/dm-1: 146.8 GB, 146796539904 bytes
255 heads, 63 sectors/track, 17846 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x69205244

This doesn't look like a partition table
Probably you selected the wrong device.

Device Boot Start End Blocks Id System
/dev/dm-1p1 ? 13578 119522 850995205 72 Unknown
Partition 1 does not end on cylinder boundary.
/dev/dm-1p2 ? 45382 79243 271987362 74 Unknown
Partition 2 does not end on cylinder boundary.
/dev/dm-1p3 ? 10499 10499 0 65 Novell Netware 386
Partition 3 does not end on cylinder boundary.
/dev/dm-1p4 167628 167631 25817+ 0 Empty
Partition 4 does not end on cylinder boundary.

Partition table entries are not in disk order

Disk /dev/dm-2: 57.1 GB, 57124569600 bytes
255 heads, 63 sectors/track, 6945 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x69205244

This doesn't look like a partition table
Probably you selected the wrong device.

Device Boot Start End Blocks Id System
/dev/dm-2p1 ? 13578 119522 850995205 72 Unknown
Partition 1 does not end on cylinder boundary.
/dev/dm-2p2 ? 45382 79243 271987362 74 Unknown
Partition 2 does not end on cylinder boundary.
/dev/dm-2p3 ? 10499 10499 0 65 Novell Netware 386
Partition 3 does not end on cylinder boundary.
/dev/dm-2p4 167628 167631 25817+ 0 Empty
Partition 4 does not end on cylinder boundary.

Partition table entries are not in disk order

Disk /dev/sdc: 100.0 GB, 100030242816 bytes
255 heads, 63 sectors/track, 12161 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000d2a83

Device Boot Start End Blocks Id System
/dev/sdc1 * 1 12161 97683201 c W95 FAT32 (LBA)

[lmarmisa]

Hmmm. The problem is not so simple as I supposed. Are you using some RAID solution?. How many hard drives have you connected?.

[MrGrado]

There are 3 hard drives at the moment. There is a 2TB drive, a 200GB drive, and a 100GB USB HHD.

Ubuntu is on the 2TB drive, Kubuntu is on the 100GB USB drive in live CD type form and there is no other operating systems.

There is no raid array.

[lmarmisa]

And what about the devices /dev/dm-x?. What are theses devices?. What hard drive do you wish to remove?.

[lmarmisa]

Your 2 TB is using GPT and fdisk does not support this option.

Try to post the result of this other command:



sudo parted -l

[MrGrado]

I suppose those dev/dm-x devices are part of the 200GB drive, which is the drive I want to remove.

[MrGrado]

mrgrado@GradoBox:~$ sudo parted -l
[sudo] password for mrgrado:
Model: ATA Maxtor 6L200M0 (scsi)
Disk /dev/sda: 204GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 32.3kB 147GB 147GB primary ntfs boot
2 147GB 204GB 57.1GB primary ntfs


Model: ATA WDC WD20EARS-00M (scsi)
Disk /dev/sdb: 2000GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt

Number Start End Size File system Name Flags
1 17.4kB 1018kB 1000kB bios_grub
2 1018kB 1998GB 1998GB ext4
3 1998GB 2000GB 2147MB linux-swap(v1)


Model: ST910082 4A (scsi)
Disk /dev/sdc: 100GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 32.3kB 100GB 100GB primary fat32 boot, lba


Model: Linux device-mapper (linear) (dm)
Disk /dev/mapper/nvidia_egfaaafb: 204GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number Start End Size Type File system Flags
1 32.3kB 147GB 147GB primary ntfs boot
2 147GB 204GB 57.1GB primary ntfs


Warning: Unable to open /dev/sr0 read-write (Read-only file system). /dev/sr0
has been opened read-only.
Error: /dev/sr0: unrecognised disk label

mrgrado@GradoBox:~$ ^C
mrgrado@GradoBox:~$

[lmarmisa]

The last command sudo parted -l did not show your 100 GB hard drive. I suppose that this disk is still there but the command was not able to show it.

I am not sure that the GRUB loader can be easily installed in your 2 TB hard drive taking into account that this drive is using GPT and not MBR.

So, I recommend to install GRUB in the MBR of your 100 GB hard drive.

Please, follow this procedure. Boot into Ubuntu and type the command:



sudo fdisk -l


Check if the 100 GB hard drive is detected as device /dev/sdc. If so, type this other commands:



sudo update-grub
sudo grub-install /dev/sdc


Shutdown your system.

Then enter your BIOS menu and select the 100 GB hard drive as boot device. I think that you will be able to boot your system from this 100 GB device. If the boot is successful, remove your 200 GB hard drive.

I hope that you will get no more problems at startup.

Best regards,

Luis

[srs5694]

It appears that you've got some remnants of a motherboard-based software RAID (aka "fake RAID") configuration -- that's what the /dev/dm-1, /dev/dm-2, and /dev/mapper/nvidia_egfaaafb device files represent. If that leftover data is stored on /dev/sda (which I assume is the drive you want to remove), it should go away once you remove the drive. AFAIK, this is not likely to be related to your problem; however, I'm not an expert on this type of RAID.

My suspicion is that you just need to re-install GRUB. There are several ways to do this. The way I'd do it is as follows:



Download Super GRUB 2 Disk (http://www.supergrubdisk.org) (note the "2") and burn a copy to CD.
Physically remove /dev/sda.
Boot using Super GRUB 2 Disk. It should give you several options to detect your OS. You may need to try several of these. Try them until you find one that works.
Once you're booted into your regular system, type "sudo grub-install /dev/sda" in a terminal window.
Remove the Super GRUB 2 Disk from the CD/DVD drive.
Reboot. The computer should now boot normally from the hard disk.



If Super GRUB 2 Disk can't detect your installation, then you may need to attempt another method of installing it to the hard disk. There are ways to do this before removing /dev/sda or by using the Ubuntu installer, but I don't have exact procedures or commands memorized. (Perhaps just "sudo grub-install /dev/sdb" would work after booting with /dev/sda installed, but I'm far from certain of this.) Somebody else may post a suggestion along these lines.

[srs5694]

I am not sure that the GRUB loader can be easily installed in your 2 TB hard drive taking into account that this drive is using GPT and not MBR.

It can be installed. The disk already has a BIOS Boot Partition (http://en.wikipedia.org/wiki/BIOS_Boot_partition) on it -- that's what the "bios_grub" flag in the parted output indicates. Thus, GRUB 2 should detect and use the GPT partitions and the BIOS Boot Partition without problems.

[lmarmisa]

It can be installed. The disk already has a BIOS Boot Partition (http://en.wikipedia.org/wiki/BIOS_Boot_partition) on it -- that's what the "bios_grub" flag in the parted output indicates. Thus, GRUB 2 should detect and use the GPT partitions and the BIOS Boot Partition without problems.

My proposal (post #10) was cautious because I thought that a bad installation of the GRUB loader in the 2 TB hard drive could damage the data structures of that device. But I think that installing the GRUB loader in the MBR of the 100 GB hard drive is a valid solution too.

What command do you propose?. Simply?



sudo grub-install /dev/sdb

[srs5694]

GRUB 2 is GPT-aware, so there's little risk of a GRUB 2 re-installation damaging the GPT data structures. The only way that would happen would be if there were a bug, if the GPT data structures were damaged, or if there's a hardware error. These would be risks when re-installing GRUB to an MBR disk, too, and they're very minor risks. Of course, backing up your data is in order, but that's no more true of this situation than of any other.

I suggested a procedure in my earlier post (#11 in this thread).

[YesWeCan]

If you boot into Ubuntu on the 2TB as usual and run
sudo grub-install /dev/sdb
As has already been suggested twice. That should work.
Also run
sudo apt-get install dmraid
To see which disks have old Windows RAID superblocks on them
sudo dmraid -s
Remove from a disk using
sudo dmraid -Er /dev/sdx (x=a,b,c as required)