Linux on Portable SSD

Goal: Have an external SSD capable of booting Linux simply by plugging it into any PC.

Requirements

• USB Drive >= 16 GB

• External Drive (SSD, USB or HDD) >= 32 GB to install Linux on

Tutorial

For any PC to be able to detect the SSD as bootable, the SSD must include an esp - efi partition (300mo fat32), which is how the bios detects the SSD as a boot option.

1. Prepare a bootable Ubuntu USB or any linux (I recommend Kubuntu). If you have a fast USB Drive >64 GB, I recommend to install Medicat.

2. Boot on USB (use safe graphics if it crashes)

3. Start linux install, when asked, select custom partitioning

4. Here are the partitions you need to create on your external Drive:

   • root:

   type: ext4

   mount point: ‘/’

   size you want for the OS eg: 75 GB

   • efi:

   type: fat32

   mount point: '/boot/efi'

   size: 300MB

Here is how it should look like (ntfs if you want to use free remaining space as usb drive):

Here I formatted the free space to NTFS to use the free space as an external Drive in any OS

1. Continue install normally

2. Done, now you can boot on your external drive by choosing the right boot option

Troubleshooting

Not Booting: busybox (initramfs) prompt

Fix 1

SSD got disconnected

you can runb blkid to see if it got disconnected

1. Unplug for 5s and replug SSD

2. type exit and it should boot

Fix 2

sudo fsck -ac /dev/sda2  # your root partition

# You can also try this one
sudo fsck -f /dev/sda2  # your root partition 

Fix 3

Recover bad superblock

It happened to me many times that for no apparent reason my PC wont boot into linux on my external SSD, it would just load for a really long time and end up on a busybox (initramfs) prompt. This was really frustrating. I think it has something to do with force shutdown... Fortunately, I've found how to fix that. Check https://www.cyberciti.biz/faq/recover-bad-superblock-from-corrupted-partition/

1. Boot into Live USB Installation made before, Try Kubuntu

2. Plug your external SSD

3. Identify your root partition number with command lsblk, mine was sdb2

4. sudo su

5. dumpe2fs /dev/sda2 | grep superblock

Sample Output:

  Primary superblock at 0, Group descriptors at 1-6
  Backup superblock at 32768, Group descriptors at 32769-32774
  Backup superblock at 98304, Group descriptors at 98305-98310
  Backup superblock at 163840, Group descriptors at 163841-163846
  Backup superblock at 229376, Group descriptors at 229377-229382
  Backup superblock at 294912, Group descriptors at 294913-294918
  Backup superblock at 819200, Group descriptors at 819201-819206
  Backup superblock at 884736, Group descriptors at 884737-884742
  Backup superblock at 1605632, Group descriptors at 1605633-1605638
  Backup superblock at 2654208, Group descriptors at 2654209-2654214
  Backup superblock at 4096000, Group descriptors at 4096001-4096006
  Backup superblock at 7962624, Group descriptors at 7962625-7962630
  Backup superblock at 11239424, Group descriptors at 11239425-11239430
  Backup superblock at 20480000, Group descriptors at 20480001-20480006
  Backup superblock at 23887872, Group descriptors at 23887873-23887878

1. fsck -b 32768 /dev/sda2 # Just Press enter as long as its asking

Sample Output:

fsck 1.40.2 (12-Jul-2007)
e2fsck 1.40.2 (12-Jul-2007)
/dev/sda2 was not cleanly unmounted, check forced.
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Free blocks count wrong for group #241 (32254, counted=32253).
Fix? yes

Free blocks count wrong for group #362 (32254, counted=32248).
Fix? yes

Free blocks count wrong for group #368 (32254, counted=27774).
Fix? yes
..........
/dev/sda2: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sda2: 59586/30539776 files (0.6% non-contiguous), 3604682/61059048 blocks

1. Done, now try to reboot on your external SSD and it should work.

---

if you reinstalled your main OS and your PC won't automatically boot on the SSD when it's 1st in the boot order, follow these quick steps:

1. Go in BIOS and manually boot on your external drive (select the OS manager EFI partition, not the USB Drive entry itself)

2. Follow this screenshot to reorder your boot option to ensure ubuntu is first.

   
3. If it still doesn't work, go in BIOS and set low boot priority to USB so it will first boot on grub and not on the default USB boot option that will lead to a boot loop.

---

If you have new chipset error or long boot try these:

1. sudo gedit /etc/default/grub

2. Replace GRUB_CMDLINE_LINUX_DEFAULT="quiet splash" with GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset nouveau.modeset=0"

3. save & exit

4. sudo update-grub

If you just have a long boot try to disable secure boot in bios.

---

Fixed in Ubuntu 24.04 releases

At the time of writing this tutorial, the Ubuntu installer has a problem: the disk selected for installing the bootloader (GRUB) is not currently the one on which GRUB will be installed, GRUB will be installed on the first efi partition detected, in other words, in the case of a Windows PC, GRUB will be installed on the Windows PC and therefore the SSD will not be bootable on another PC, and the Windows PC will no longer boot when the external SSD is unplugged. To remedy this, in a live Ubuntu for example and using gparted, remove the boot and esp flags from any disk, create the efi partition on the external SSD with the boot and esp flags. Install, then reset the flags. This way, the only disk to have the flags will be the external SSD.

before it was necessary to add these steps after 2.

• Enter in mode "try ubuntu" to create EFI partition (this step is crucial, it enable the portability of the drive, it allows the drive to have its own boot option so that any PC can detect it)

• open gparted, select your external drive (NOT LINUX USB), create FAT32 500 MB partition , then right click on it, manage flags, boot + esp.

• remove boot+esp flags from your PC main OS to ensure grub will install on the external drive and not on your PC (currently ubuntu install has this bug where it always selects the first EFI partition detected to install grub on it). AND at the end add back the boot+esp flags on original drive:

• Once you are in ubuntu, do sudo update-grub and install gparted to re-enable the EFI flags on your PC's main OS: sudo apt install gparted re-enable boot + esp flags for the drives that had it before step 5. (basically your boot drives, C: drive on windows)