Installation does not "see" other partitions / OS

[rdh61]

Hi,

I am trying to install Ubuntu 12.04 from the live CD, on a desktop computer on which I have Windows XP and Ubuntu 10.10 on separate partitions.

During installation the process does not find any OS already on my computer, and only offers me one device on which to install 12.04, i.e. the whole disk.

How can I proceed with the installation without wiping out my Windows installation?

Many thanks.

[coffeecat]

Hi, I can think of two reasons why the installer cannot see pre-existing operating systems. First - there could be an illegality in your partition table. Second - residual RAID metadata on a hard drive now used as a single drive can also confuse the installer.

Boot up the live CD and choose "try Ubuntu" to get to the live desktop. Open Gparted and take a screenshot (Alt+Print) of the open Gparted window, and post the screenshot. If there is a partition table irregularity, Gparted will probably falsely show the whole drive as "unallocated". Also, open a terminal and post the output of this command:

sudo fdisk -lu

This will give us the information in your partition table. For pasting the output into your post, you can highlight it with the mouse, right-click -> copy.

Was the hard drive ever used in a RAID?

[rdh61]

Thanks for your reply.

I had to look up RAID. No I have never done that.

Gparted screenshot attached.

Output from sudo fdisk -lu ...

ubuntu@ubuntu:~$ sudo fdisk -lu
omitting empty partition (5)

Disk /dev/sda: 250.1 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders, total 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: 0x621e939d

Device Boot Start End Blocks Id System
/dev/sda1 * 63 244155869 122077903+ 7 HPFS/NTFS/exFAT
/dev/sda2 244155994 488392064 122118035+ 5 Extended
/dev/sda3 484488333 488392064 1951866 82 Linux swap / Solaris
/dev/sda5 244155996 484488269 120166137 83 Linux

Disk /dev/sdb: 7873 MB, 7873757184 bytes
243 heads, 62 sectors/track, 1020 cylinders, total 15378432 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
ubuntu@ubuntu:~$

[zSeries]

I had the same problem on one of my installs of 10.04, I have 7 disks in 4 PC's. After booting the Live CD go to Synaptic Package Manager and remove dmraid (assuming you dont want to use raid) and try again.

[rdh61]

Thanks, but Synaptic tells me dmraid is not installed.

[coffeecat]

First thing - I can't see any illegalities in the partition table in the output of fdisk, but Gparted is showing "unallocated" which is what happens when there is. So I'm somewhat puzzled at the moment.

About RAID and the package dmraid. Simply uninstalling dmraid would not remove RAID metadata which is the other possible problem, even though you are sure the hard drive has not been used for RAID. You say that dmraid is not installed - I assume you mean in your 10.10 installation which would not be surprising since dmraid is not installed by default. And what is or is not installed in 10.10 would be irrelevant to your problem anyway. However, it is present in the live CD session and we can use it to see if there is indeed RAID metadata on your hard drive for whatever reason.

Boot up the live CD and go to the live desktop, open a terminal and run this command:

sudo dmraid --raid_devices -v

Do you get the message "no raid disks" or "INFO: RAID device discovered:"? If the latter, please post the entire message - there will be another line - and we'll take it from there.

[zSeries]

I just download and burnt a 12.04 Live CD. dmraid is installed. Please check that again. I suggested this because I have never used raid and the disk I had the problem with was already working on one 10.04 machine and I just moved it to another machine for a fresh re-install. It was a while ago I did this but I think this is the link that prompted me to remove dmraid.

http://askubuntu.com/questions/56069...ing-hard-drive

I hope it helps.

[coffeecat]

@zSeries, please read my post again. The package dmraid is included in the live CD but it is not included in a default installation to a hard drive. The OP reports that synaptic says that dmraid is not installed which suggests to me that the OP is reporting on their permanent installation of Ubuntu 10.10. Besides, synaptic is not included in 12.04 either by default or in a permanent installation. The OP is using the 12.04 live CD so your suggestion to open Synaptic in the live 12.04 session is simply not going to work, because Synaptic is not there.

The askubuntu link you post is interesting but I am trying to determine a slightly different point. Residual RAID metadata can cause the problem the OP is describing, and I have seen threads where the OP thinks they have never used the hard drive in RAID, yet RAID metadata turns out to be the problem. I want to see if this is the case here. The dmraid command I suggested will tell us this. If this turns out not to be the case, I agree it would be a good idea to try to remove dmraid from the live session as suggested in the askubuntu link, but the OP would need to use apt-get from the command line to do this, not Synaptic.

[rdh61]

@coffeecat

ubuntu@ubuntu:~$ sudo dmraid --raid_devices -v
no raid disks
ubuntu@ubuntu:~$

I can confirm that I have never used RAID , I didn-t even know what it was! When I took this computer over from someone else the HD was replaced with a new one, and I am the only one who has used the computer since.

@zSeries / coffeecat

I can confirm that on the pre-existing Ubuntu OS - 10.10 - dmraid is NOT installed.

Thank you for your efforts to help.

[coffeecat]

OK - it was a long shot but useful that we've excluded that as a possibility.

zSeries' suggestion is a good one, so try that next. What you would need to do in the live CD session (12.04) is to open a terminal, and:

sudo apt-get remove dmraid

(It's in the askubuntu link that zSeries posted.)

Out of interest, once you've run the apt-get remove command and removed the dmraid package, open Gparted and tell is whether it is still showing "unallocated", or whether it is showing your partition layout. Now start the installer and see whether it can now see your Windows and Ubuntu 10.10 installations.

The reason I ask is that the OP in the askubuntu page was able to use Gparted to edit partitions, but you are not, so it will be interesting to see if uninstalling dmraid helps in your situation.

If it doesn't, don't despair. I'll ask some other people to have a look to see if they have any suggestions.