Win 7 Installation and Hard Drive Confusion

Asked by Vernon Balbert

I suspect that my situation may be rather unique. I have three hard drives, two identical 250 GB drives and one 1 TB drive. I had formerly had Windows 7 installed on the two 250 GB drives as a striped RAID. I didn't notice any real performance increase so I've split the two drives up. On the first drive I have a 104 MB partition that was placed there by the Win 7 installation and the rest of the drive formatted as NTFS where Win 7 is installed. The 1 TB drive is used for data and has no operating system files on it, but it is formatted as NTFS. The 250 GB drive is empty and has either had either a partition that occupied part of the disk or (as it is now) unpartitioned.

When I try to install Ubuntu 10.04 it doesn't recognize 3 distinct drives. Instead it shows this:

/dev/mapper/pdc_eacdagdagc
 /dev/mapper/pdc_eacdagdagc1 104 MB Unknown
 /dev/mapper/pdc_eacdagdagc2 249952 MB Unknown
 Free Space 250060 MB

It shows the 1 TB drive as /dev/sdc1. Now it's my opinion that the 2500060 MB is the second 250 GB drive on which I'd like to install Ubuntu, but what I don't understand is why it's not showing up as /dev/sdc2 nor why the first drive (with Win 7) is showing up as /dev/sdc1. nor the 1 TB drive as /dev/sdc3. I suspect that because the two 250 GB drives were at one time configured as a RAID that it may have left some "debris" that makes Ubuntu think that it's still a RAID. How can I fix this so that things appear as I expect it should?

Question information

Language:
English Edit question
Status:
Solved
For:
Ubuntu Edit question
Assignee:
No assignee Edit question
Solved by:
Vernon Balbert
Solved:
Last query:
Last reply:
Revision history for this message
Peter (dead-meat-thompson) said :
#1

1St read ALL <--- of this,

The thing about RAID is when you '' split the array you usually end up having to reinstall the O/S because near as i can tell your dealing with a hardware RAID which is what '' pdc_eacdagdagc is about not sure what type of mobo your using but if you go into the controller config and set it as JBOD it will separate the disks into individual volumes HOWEVER!! CAUTION, this can blow away the contents of these disks so you need to backup before even attempting something like this!! as goes your raid you would be better off with raid 1 as this offers redundancy at a minimal performance cost. but again BACKUP, BACKUP, BACKUP! hope this helps.

Revision history for this message
Vernon Balbert (vbalbert) said :
#2

I had backed up my hard drive before I "disassembled" the RAID, reinstalled the OS from scratch and restored the data rather than restoring the backup entirely. The BIOS is not configured for any type of RAID, the BIOS recognizes all three drives as separate, the RAID BIOS configuration does not appear on boot (as it did when I had the system configured for RAID) and Win 7 recognizes all the drives as separate rather than any of them as RAID. I do not have it configured as JBOD either. (FWIW, I'm using an MSI NF980-G65 motherboard.) The only thing incorrectly assumes that I still have a RAID configuration is Ubuntu's installation program.

Revision history for this message
actionparsnip (andrew-woodhead666) said :
#3

fyi:

/dev/sda is a disk
/dev/sda1 is the first partition on a disk

Windows incorrectly names partitions drives like "C drive" and "D drive". You can have a single physical disk in windows with 2 partitions and you will get a "C drive" and a "D drive" despite their being only 1 drive with 2 partitions.

Watch your use of the words drive and partition as you could confuse the thread.

Revision history for this message
Vernon Balbert (vbalbert) said :
#4

Oy! Pedants are going to give me a headache, especially when you start assuming I wrote one thing

I have THREE physical hard drives. The Ubuntu install program sees only ONE physical hard drive and assumes the other TWO physical drives are ONE RAID drive when in fact, they are TWO separate drives. Is that so hard to determine from my messages? Windows sees all THREE physical hard drives. The BIOS sees THREE physical hard drives. For some reason the Ubuntu installation program the TWO physical hard drives as one RAID drive when in fact, RAID is not configured on my machine. At no time did I say that there was anything else, I never mentioned drive C: D: or any other letters. I spoke about how the drives were partitioned, but I never mentioned any letters.

Revision history for this message
David Mawdsley (dm-madmod) said :
#5

As a comment, why not temporarily disconnect the 2nd and 3rd drives and boot into Ubuntu, update grub and then shut down. Next connect the 2nd drive, boot into Ubuntu and see how things are going.
If two drives are now "seen", shut down and reconnect the 3rd drive. Restart Ubuntu and see if there are now 3 drives. Perhaps by then the RAID confusion will be gone. If the RAID confusion continues probably either drive 2 or 3 didn't get reconfigured.

Revision history for this message
Peter (dead-meat-thompson) said :
#6

Sorry about that had to step away a minute, so amd ddr3 solid choice of mobo, so anyhow i guess if you turned it ( the RAID configuration) all off and you dont get the f10 prompt for it anymore the next step is to double check the drives like you said, david is right though if you pull em one at a time that could work if not though i dont know which live media your using but if you boot from it you could always use gparted to double check the drives, that should be in the system tools folder once your booted all the way in and that should tell you pretty much everything about the drives and how they are set up plus if you do have clutter on them hat would be the thing to use to clean em off, did'nt know about the clean install but ive seen it happen where people get all bent out of shape where something is assumed so figured i should just mention the back it all up pretty please.

Revision history for this message
Vernon Balbert (vbalbert) said :
#7

I will try using the single drive setup to see what happens, but that will have to wait for tomorrow. I'll let you know how it goes.

Revision history for this message
Vernon Balbert (vbalbert) said :
#8

I tried the single drive setup and it worked, however I went a little farther in my experimentation. After it was installed I reconnected the other two hard drives and then booted into Windows (I realize that it wouldn't boot into Ubuntu because the boot drive doesn't have GRUB installed) and then deleted the partitions created by Ubuntu and then rebooted to the install CD. The partitioning software again thought that the two 250 GB drives were a single RAID 0 array with 250 GB of unpartitioned space. Something in the Ubuntu install is insisting on loading software RAID drivers. (This is besides the irritating fact that it the install program doesn't recognize the Win 7 installation. This is, IMHO, a serious defect in the install program.) It appears that there is something in the MBR of either one or both of the 250 GB drives that is causing the install program to start up the software RAID driver. This invites two options:

1) If something in the MBR is causing the software RAID driver to take over, what is it?

2) Is there a way to keep the software RAID driver from starting?

Revision history for this message
Peter (dead-meat-thompson) said :
#9

Ok i tried to load this onto a netbook with win 7 on it and got kinda the same thing with the non recognition of win 7 the way i got around it was using gparted to make the 7 install smaller ( could be done on the install ) but who cares, anyhow i moved the back of the 7 partition forward so i had room on the back of the drive ( since yeah reinstalling the O/S would be a huge pain). as i said earlier parted could be used to totally blank the drives and if you right click on the drive it should bring up a box. in that box is the manage flags tool just double check that there are no flags on the drives that say raid cos that would do it, all of this is when you boot from the live media into ubuntu, i might just be making a noise instead of a point because it might show the same as on the install boot but at least you could use it to kinda get some sort of clues and all else fails totally scrub the partitions off the drives and set them totally blank. as goes stopping the raid driver from starting no go i think i might be wrong here but i know enough to say that ubuntu relies upon the same system to create its lvm so i dont think you can take it out of the equation. <-- open to being wrong on that and interested to know if i am.

Revision history for this message
Vernon Balbert (vbalbert) said :
#10

I think I've found the problem and it appears that the device mapper is trying to configure for software RAID when it shouldn't be doing this. It's nothing on my drives (I even wiped the MBR on the drive with no partitions to make sure.) Unfortunately there's no way to turn it off on the regular install CD but there is a non-graphical version of the CD that will (I hope) allow me to send kernel parameters and turn off the device mapper. Hopefully I can blunder through this and figure out how to get the graphical interface to start when I get this thing installed.

I find it rather disconcerting that with one of the most popular distros of Linux that nobody came up with this before me, a person who is relatively ignorant of Linux. It makes me wonder if I should be using Ubuntu since the community help does not seem to consist of people who know how the OS works.

Revision history for this message
Peter (dead-meat-thompson) said :
#11

yeah sorry dude wish i could be more help, this is why i switched to fedora, i use ubuntu for terminals mostly so i might be applying the wrong principals

Revision history for this message
David Mawdsley (dm-madmod) said :
#12

Another comment: my take on this is that the RAID was created in the Windows environment and so the mbr still remembers the RAID even though with the live CD and Ubuntu it appeared to be deleted. Ubuntu didn't change the mbr that Windows was using.

What I'd do is to boot into safe mode with a command prompt (use F8) with only one drive connected. Then issue the DOS commands separately: fixmbr and fixboot and use the command: exit to finish up in DOS. Restart to see that Windows 7 is okay.

At that point you may be able to restart with the Ubuntu live CD and install Ubuntu on a second partition of the single drive. Use ext4 if there's an option for the file system type. The installation should find the Windows 7 and allow for reallocating its space to a lesser portion so the ext4 for Ubuntu has the room it needs -- basically at least 10GB is right. At the end of the install the computer when restarted should show an option screen to choose either Windows 7 or Ubuntu and you're good to go at this point.

Finally you should be able to reconnect the other drives with the power off and then restart. With Ubuntu you should be able to reformat the 2nd and 3rd drives for NTFS so both operating systems can use them. Good luck on this!

Revision history for this message
Vernon Balbert (vbalbert) said :
#13

A) This was a hardware RAID installation, not a software one. Windows instantly saw this as a RAID when I installed it.

B) The RAID was later disabled. Windows instantly saw the two drives as two distinct physical drives and installed to the drive I specified without any hassle. (And no, there were no drive letters to choose as the drives did not even have a recognized partition on them when I installed Windows.)

C) Ubuntu's desktop install CD does not see Windows 7 installations on many systems as I have seen when I was researching this problem before I started this thread.

D) Ubuntu's install program INSISTS on enabling DMRAID on installation. There is NO WAY to turn this off with the desktop installation disc. The alternative install disc (which is text based and not GUI) wanted to do this but I was able to turn it off. Even so, later in the installation I had to specifically tell it NOT to use DMRAID. Finally, the alternative install didn't even give me an option for which drive I wanted to use in the guided partitioning.

E) The support community does not seem to be aware of the device mapper and how it works. I, a user relatively ignorant of Ubuntu was able to determine where the problem is before any of what I expected to be more experienced people were able to determine.

This indicates a major failure of the Ubuntu install system and support community. Disconnecting hard drives just to install an OS is not a viable option. It is a kludge at best.

As much as I liked the look and feel for Ubuntu, I'm afraid I'm going to have to go with another distro. I'm calling this solved despite the fact that it's a problem that many users will face.

Revision history for this message
David Mawdsley (dm-madmod) said :
#14

If you're certain it's a hardware installation of RAID, then there should be an option in the BIOS for turning it off or on. Perhaps a quick check of this would determine if that's what has happened.

By the way, if BIOS has turned it on, then software fixes or reinstalls won't make any difference. My take on RAID also is that it will expect at least 2 disks for even a minimum install of RAID and could take 4 or more for RAID 10.

I'm afraid that's the best I can do for you. Perhaps someone in the Fedora community can help. This is a free forum after all. Maybe a paid account with Red Hat would be more productive.