install 12.3 with Win 7 on 2nd harddrive

My wife just got a Win 7 (64-bit) pc, and she wants dual-boot Win7/SUSE. Our tech guys installed a second hard drive. Now, I want to have SUSE 12.3 on this second hard drive. I also want to keep Win 7, with a dual boot configuration. I’m uncertain about the partitioning step of the installation. Is there a good step-by-step guide on how to do this?

Any help is appreciated. I’ve done this on an older WinXP machine, using Grub, but I recall it being easier. Maybe, I was just not as wary of making a mistake; this is my wife’s computer after all.


It can be done. openSUSE must be manually partitioned for this to work.

  1. You must select the external hard drive as the boot drive in your BIOS setup.
  2. See the screen shot below. In the booting section, you must set the "Order of Hard Disks to read “/dev/sdb, /dev/sda” in order for the grub 2 boot loader to be sent to the external hard drive.
  3. In the same screen below, you want grub2 to be located in /dev/sdb2.
  4. In the same screen below, you want to boot “/” just as show.

5. You want to set the grub 2 boot loader to load generic boot code into the MBR.
6. You must set the root partition as the active boot partition
7. Suggested partition setup for the external hard drive.

  1. /dev/sdb MBR formatted haed drive. Generic boot code loaded into MBR
  2. /dev/sdb1 Primary Partition, 4GB SWAP
  3. /dev/sdb2 Primary Partition, 60 GB EXT4 root “/”, Active boot drive
  4. /dev/sdb3 Primary Partition, rest of disk, EXT4 “/home”

Ask more questions on what is shown.

Thank You,

100% right James if the BIOS is not UEFI.

That we don’t know. If this is brand new hardware with Win 7 on it then it is possible that it is EFI if older hardware it maybe the old BIOS. Only the OP can tell us.

No matter, I would try a MBR formatted external hard drive and hope it allows easy switching between the two hard drives running Windows & openSUSE.

Thank You,

Hi chaddy,
and where is the problem?

Not something unusual.

Ha, great - not even a single change necessary on the 1st HDD that has windows on it.

Seperate HDD - very good conditions.

Keep it, it’s on the 1st HDD, don’t see any problem.

Don’t mind.
Do any partitioning that you like, as long as it takes place on the 2nd HDD
which you earmarked for Linux/openSUSE.

A real point is the bootloader, like e.g. legacy GRUB, or GRUB 2,
and the boot mode - UEFI or non-UEFI.

Is that system booted in UEFI mode or not?
Or can you select that?

Best wishes

Thanks for the advice. I’ve set up the installation and took some screenshots (ie, photos with my camera). I haven’t pulled the trigger yet, though. Does this setup look okay?

Index of /phsc-faculty/cyoung/TMP/linux_install

By the way, I don’t know if it is UEFI. I found this file on the computer: C:\Windows\Panther\setupact.log

It contained this line:
Callback_BootEnvironmentDetect: Detected boot environment: BIOS

It is my understanding that this means it is not UEFI, but I don’t really know what UEFI is. I did enter the BIOS setup, and it did say something about UEFI.

Thanks again for all your help. Hopefully, by tomorrow afternoon, I’ll have her running.


You may have a UEFI BIOS but running Windows under a legacy BIOS cofig. So I’d follow James’s advice.

The boot section looks correct. There is no way here to know if you checked to load generic boot code into the MBR in the openSUSE bootloader. External hard drives will have a blank MBR by default and not boot. I suggest using 60 GB root, not 20 GB. Else, it looks good.

Thank You,

James et al.,

Thanks for the info and advice.

I tried to change the root from 20 to 60 Gb, but it said that 20 Gb was the max (and 42Mb was the min). I left it at 20 Gb. Otherwise, I left everything else unchanged.

The installation went through okay, I think, but, when I restart the computer, it loads into Windows. I checked the BIOS to see if it was booting off of the second HD; it was not even though I had selected this in the installation. Anyway, I moved the 1TB 2nd HD to first in the boot order sequence, but the computer still booted to Win7. For some reason, it is not booting off of this 2nd HD.

BTW, when I do load into Win7, I can no longer read the 2nd HD. Win7 wants to reformat it.

Not sure where to go from here…any advice is appreciated.


So if you backed up far enough, you could have redone the partition sizes and I did suggest 60 GB. As for the boot loader settings, I don’t think elected to load the MBR with generic boot code.

Notice the write generic boot code to the MBR is checked. Why can’t you just reinstall openSUSE, delete the partitions and try again?

Thank You,

Hi James,

Again, thanks for your help.

For Boot Loader Location, under Boot Loader Settings, should I have this checked to “Boot from Master Boot Record,” since I am writing the boot code to the MBR?

I tried reinstalling with the changes above, but still it went to Win7 when booting. Changed the boot order of drives in BIOS, but still went to Win7.


Hi James,

Thanks again for your help. I have it up and running; my wife is very happy and is in the process of moving everything over.

These are screenshots from my latest installation:
Index of /phsc-faculty/cyoung/TMP/linux_install

I was still not able to get the 60Gb root, though I did find the place to change it. I gather this won’t cause an issue for her work.


Not sure why James suggested a 60 gig root. Maybe I missed something since 20 gig should be fine for normal desktop use. If you did go to 60 gig you would also need to reduce home by 40 to allow room.

No matter if 30 to 60 GB, running out of space on root / is bad and in numerous installs, 60 GB has not been exceeded while 20 GB has. My laptop right now lists root / as using 21.2 GB out of 78.6 GB I allocated in it. To hold root below 20 GB will require sticking with one desktop and loading only the applications you use all of the time. I prefer loading both KDE and GNOME along with all of the apps I have ever used.

Thank You,

I have created a blog on the subject that can be found here: Installing openSUSE 13.1 onto an External Hard Drive

Thank You,