How to get external USB-SSD to Boot on Laptop - Super User most recent 30 from 2019-05-21T10:50:01Z 1 How to get external USB-SSD to Boot on Laptop user6287736 2017-12-24T22:56:35Z 2017-12-25T05:51:36Z <p>Thanks for considering helping with this issue!</p> <p>I am struggling to get an external USB-SSD to boot (Ubuntu and grub installed on it) on my Dell XPS 15 l501x Laptop.</p> <p>The issue there is that the external Disk is powered by the USB ports only a few seconds after the bios has scaned for bootable media. Afterwards, the drive's partitions can be used as storage.</p> <p>There is no reason why this wouldn't work. It works flawlessly on my PC. It did work a few times on the Laptop (each of these times way immediately after playing around with the bios settings or the USB cable (got a Y-cable to make sure there really is be enough power)) but fails 99% of the time.</p> <p>I tried many combinations of bios setting, switched each setting on and of individually but no success. </p> <p>The Laptop's battery is broken but it is plugged into the wall. I don't think that the small amount of extra power needed for the USB-SSD exceeds the power supply (I also tried with the internal HDD disconnected which should then have freed up enough power).</p> <p>Since this problem can probably not be solved directly, is there a way to make grub (on the internal drive) re-scan for external drives and then boot from them? I tried just adding </p> <blockquote> <p>set root(hd1,7)</p> </blockquote> <p>but grub only finds hd0 so it would probably have to re-scan.</p> <p>So, I really don't have any idea what else to try and therefore need your ideas and knowledge to find the solution for this. I am so grateful for any help you can provide!</p> 1 Answer by Doug Millar for How to get external USB-SSD to Boot on Laptop Doug Millar 2017-12-25T05:51:36Z 2017-12-25T05:51:36Z <p>We have had similar issues with external HDDs. Sometimes the USB port cannot supply enough power to the external device. Should be 5 Volts. The solution is a powered USB hub between the laptop USB port and the external device. The hub has a separate power supply such as an AC adapter. Maybe your Y-cable should work, but I don't know exactly what your hardware setup is. Myself, I would verify it. I boot Ubuntu from a USB memory (memory stick) in a laptop for years without problem.</p>