Installing opensuse on an external drive — MBR version

This post describes my experience with installing on an external drive.  I tested this with 13.1 Beta1 on an MBR based computer.  I later repeated with the final version of 13.1 on a UEFI box, and I’ll report on that in a future post.

I first tested this using the live KDE media, written to a USB flash drive.  I later repeated using the DVD iso, also written to a USB flash drive.  Overall, the install went rather well.  But there are a few places where care is needed.

Booting the installer

I had the install software on a USB flash drive.  I wanted to install on a USB hard drive.  The BIOS on the target computer has an option to boot from a USB.  But it does not allow choice of which USB.

My first step was to plug in the installer flash drive (the live KDE media).  I then booted the computer, hitting F12 while it was booting.  For this particular computer, hitting F12 brings up the BIOS boot menu.  I selected “boot from USB”.  That brought me to the opensuse boot screen.  I accepted the default (boot the live media).  I immediately plugged in my USB hard drive, while it was booting, though I could have waited till a little later with live media.

The idea here was to have only one USB device connected at the start of boot, to avoid confusing the BIOS.  Once booting had begun, I could connect the other USB device.

Because I was using live KDE media, this booted me into a KDE session.  There, I clicked on the “Install” icon to start the install procedure.  If I had instead used the DVD iso, I would have booted directly into the installer.


The next place where care is required, is in the partitioning section.  The installer made suggestions on how it would partition.  The suggestions included using the primary (internal) hard drive.  I did not want that.  So I selected “Create partition setup”.

The next screen listed the disks available.  I checked only the box for the external 80G hard drive, where I wanted to install opensuse.

The next screen gave me a list of partitions on the disk.  I clicked the button “Use entire disk”.

The next screen gave me a revised list of suggestions for partitioning.  I accepted the suggests.

Boot configuration

Following the partitioning, there is a screen to enter a user login name.  After that there is a summary screen where choices can be made.  I clicked on “Booting” to configure the boot installation.

Before I clicked “Booting”, I looked carefully.  There, I could see:

Boot loader type: grub2
Status Location: /dev/sda (MBR)
(other information)

This was not acceptable.  It wanted to boot from the MBR of the internal hard drive. I wanted it to boot from the MBR of the external drive (“/dev/sdb”). So, clicking “Booting” gave me some options.

Toward the bottom of the screen, there was a large button “Boot Loader Installation Details”.  I clicked that.

The disks were listed.  I selected “/dev/sdb” (the third entry), and clicked “Up”.  Nothing happened.  So I selected the first entry (“/dev/sda”) and clicked “Down”.  That moved the entry down.  I repeated, until it was at the bottom.  Next, I move “/dev/sdc” down in the same way.  That left “/dev/sdb” at the top of the list.

I hit “OK” twice to get back to the summary screen.  The booting section now read:

Boot loader type: grub2
Status Location: /dev/sdb (MBR)
(other information)

And that looked much better, because it was using the wanted MBR.

Install and reboot

I now clicked “Install”, and that allowed the actual install to start.  Toward the end, the installer wanted to reboot into the newly installed system.

Now I had the same problem, that the BIOS can only recognize one USB device in the boot menu.  So I rebooted, hit F12 to get to the BIOS boot screen.  And now I unplugged the flash drive that I had used for the install, leaving only the external hard drive.

In case this might have confused the BIOS, I hit CTRL-ALT-DEL to force another reboot.  And I hit F12 again, and selected to boot from the USB.

This took me to the final configuration steps of install.  And then I had a working system.  I’ll note that when using the DVD iso for install, during the boot I plugged in the install flash drive, which is needed for the final configuration.  You will be prompted to plug it in, if you have not already done so by the time that it is needed.

To boot the system, I need only plug in the hard drive, hit F12 during boot, and select USB from the BIOS menu.


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About Neil Rickert

Retired mathematician and computer scientist who dabbles in cognitive science.

11 responses to “Installing opensuse on an external drive — MBR version”

  1. joey says :

    Hi, I tried to follow your instructions, but after reboot with newly installed os I got warning: Invalid partition table. I think boot is confused, because I installed open suse from my usb disk. Is there anything I can do to run my new installation?


    • Neil Rickert says :

      There’s too little information there.

      Do you always get that message when booting? Or do you only get that when attempting to boot from the USB?


      • joey says :

        Only when booting from USB (external drive).


        • Neil Rickert says :

          Can you post the output from

          # fdisk -l /dev/sdX

          where “/dev/sdX” is the device name of your USB.

          You may need to boot a live CD or similar, if you don’t have linux on your hard drive.


          • joey says :
            WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
            Disk /dev/sdc: 2000.4 GB, 2000398929920 bytes, 488378645 sectors
            Units = sectors of 1 * 4096 = 4096 bytes
            Sector size (logical/physical): 4096 bytes / 4096 bytes
            I/O size (minimum/optimal): 4096 bytes / 4096 bytes
            Disk label type: gpt
            #         Start          End    Size  Type            Name
             1          256        48127    187M  EFI System      primary
             2        48128      4257279   16.1G  Microsoft basic primary
             3      4257280    488378623    1.8T  EFI System      primary


          • Neil Rickert says :

            I added “pre” tags to your post, so that it is lined up in columns.

            That partitioning is a bit strange.

            In any case, it looks as if you have a UEFI computer. I’m guessing that the opensuse install went with UEFI booting, and did not actually put boot code in the MBR. That might be why you are getting “invalid partition table”.

            To clarify: I’m guessing that partition 2, shown there, is actually your root partition, and partition 3 is actually your “/home”. Can you clarify that?


  2. joey says :

    I cannot reply to your comment so I am starting new thread. I do have UEFI computer, but I do not want to use UEFI booting. During installation of opensuse, I chose the grub2 instead of grub-efi.

    Partition 1 is for booting, 2 is extended swap and 3 is root partition.

    If there is no other option I will reinstall opensuse using grub-efi. If there is chance to avoid it, I would be very happy.


    • Neil Rickert says :

      I cannot reply to your comment …

      I’m not sure why that happened. I think I confused the blog software by adding the “pre” (for “preformatted”) tags. But not a problem.

      Partition 1 is for booting, 2 is extended swap and 3 is root partition.

      Okay. The partition types are a bit strange, particularly the EFI type for the root partition.

      In any case, your disk is GPT partitioned, and that is confusing the installer.

      In order to boot from the MBR, with a GPT partitioned disk, you will need to create a BIOS Boot Partition. Otherwise the grub-install will fail (perhaps silently).

      If you have live media for opensuse 13.1 or other recent distro, then boot that and use the “gdisk” command. Unfortunately, “gdisk” is not on the install DVD, but it is on the live KDE, live Gnome and live Rescue media for 13.1.

      Using “gdisk”, create a new partition. You can probably fit it in the space before the first physical partition. I’ve put it in sectors 34-2047, but that’s with a 512 sector size. You are seeing a 4096 sector size, so the equiv might be sectors 5-255. Give the partition a type code of “ef02”. The grub installer should recognize that, and put some of its code there.


      • joey says :

        Thank you Neil for your patience! Can you please recommend any literature, courses, etc. where I can find more info about linux/opensuse? I am dying to study new stuff and explore new frontiers.


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