Running openSuSE from an External Hard Works like a Champ!
Since version 10.0 I have been running SuSE from an external hard drive and with version 11.2, it works with no changes out of the box. What you need is a computer BIOS that allows you to boot from an external USB hard drive. To make sure no modifications are made to your existing hard drive, I disconnect the data cable from my internal hard drive or pull out the drive on a Laptop. I boot from the install CD and direct the install to the only hard drive that exists at install time. This procedure ensures no modifications will be made to your existing hard drive.
There are two potential issues you must deal with after the install. The external hard drive must have a boot sector loaded on. On most external hard drives, the boot sector is blank. When you install SuSE, you can elect to manually replace the boot sector with a generic one. Often, I forget to do so, but I have a partition utility that allows me to copy the boot sector from my internal hard drive. Without a boot sector copied on the external hard drive, everything else can be installed properly, but it still will not boot. If you use a internal hard drive that has had any OS installed on it which booted fine, this drive can be placed in an external enclosure and work fine with SuSE.
The second issue is Windows partitions will not be automatically mounted when a drive is disconnected during the install and you will not get say a Windows boot entry in the Grub menu.lst file. The built-in SuSE partitioner can be used to mount an existing partition without reformatting it, adding it to fstab for you. Adding a Windows boot entry to grub is simple as well and we can provide examples of what to add.
If you disconnect or remove your internal hard drive, you have only time to lose by trying to load SuSE on an external hard drive. If you elect to NOT remove your internal hard drive, you must do a full backup of your internal hard drive known to be able to restore a bad Windows or other OS install. For Windows, I always use Norton Ghost which works just fine. What ever you use, you must have a boot disk you have tried, able to find your backups. Backups when made should be verified after the backup.
You have nothing to lose by trying this if you follow my suggestions. For my work laptop, this works just great allowing me to have video and audio files in SuSE, none of which can be seen by big brother company. I use this setup when working out of town. Once the office work is done, I plug in my external hard drive and boot into SuSE. This also gives you a method to fetch files from Windows should Windows stop booting for some reason through SuSE and your external hard drive.
Need more details? Just ask but don't be afraid to give it a try yourself. When I first tried this four years ago, I must have tried reloading SuSE 10.0 a dozen times before I got it to work and wiped out my Windows drive more than once, using Norton Ghost to restore my Windows partition each time. Now that was long ago and SuSE is MUCH BETTER loading on an external hard drive, requiring few changes and just disconnecting the internal hard drive ensures no problems will happen there.
Last edited by jdmcdaniel3; 02-25-2010 at 08:19 PM.