Ubuntu – How to create enough space for Steam on a persistent live USB

19.10live-usbpersistencesteamusb-installation

I'm a newcomer to Ubuntu (due to the upcoming Windows 7 EOL) and I'm trying to test Ubuntu on a bootable USB stick, but I cannot get Steam to run because of a lack of space. How should I distribute the space on my USB so that Steam & a game can be tested?

I have used Rufus 3.8 to create a bootable USB stick containing Ubuntu 19.10 Eoan Ermine with a 16GB persistent partition.* I have been able to download the Steam installer. After installing, Steam downloaded 350MB of updates. Unfortunately, it has been unable to complete the update, saying that it needs 250MB more space. This appears to be correct, as Ubuntu's 'Files' utility say that the "casper-rw" partition only has 85 MB left.

The 'Disks' utility provides a different set of numbers. It says my 32GB** stick has a 14GB FAT Ubuntu partition (with 11GB free), a 17GB ext3 casper-rw partion, and 11GB free.

I am guessing that I need to make the persistent partition larger, but several points make me wonder whether I've done something else wrong. I am surprised that the Steam installer and runtime, without any games, have used up 16GB, because an installation is only supposed to require 5 GB. I am also puzzled that there is 11GB free in the Ubuntu partition: I thought that was supposed to be a read-only partition pretending to be a live CD, so there should not be any free (writable) space at all. Given that it's there, should I be trying to install Steam to somewhere other than the default location? Or should I try using Lubuntu or Xubuntu to make the OS smaller? Surely there's some way to squeeze Ubuntu and Steam onto a 32GB stick?!

*I know Steam says you should use 18.04LTS, but Rufus requires 19.10 for persistent USBs.

**Let's not quibble about GB or GiB here as it's probably irrelevant.

Best Answer

Solution with a persistent live USB pendrive and Ubuntu 18.04 LTS

This method should work for you because mkusb is designed to work with all current versions of Ubuntu.

If you have two USB pendrives, you can make a live-only system i Windows using Rufus with 18.04.1 or 18.04.3 LTS. This could be in a smaller and/or slower drive.
Boot into this live drive.
Install mkusb into it (live-only, but it will survive until its task is done and you reboot).
Create a persistent live drive in the other bigger and/or faster USB pendrive. mkusb will create a persistent live drive with a partition for persistence and you can select 100% of the available drive space for persistence.
Boot into the persistent live system
Install Steam and enjoy :-)

Alternatives

You can use an SSD in an external box and connect via USB 3 or eSATA. This will make a very fast system, almost like it were an internal drive.
You can create an installed Ubuntu system in a USB drive, pendrive or any other kind of external drive (e.g. SSD).

Clone with mkusb

You can clone from a drive to another drive with mkusb. Start via the graphical interface or with

dus /dev/sdx

where x is the device letter or the source in the cloning operation. The target will be selected in a safe way via menus.

mkusb wraps a safety belt around dd
if there is a GUID partition table, GPT, mkusb fixes the backup partition table at the tail end of the drive. (Otherwise you must do that manually for example with gdisk.)

After the cloning you can edit the partitions with gparted. If you touch only the casper-rw partition and the usbdata partition (amd if an MSDOS partition table the extended partition), booting will not be affected.

Edit: How to edit the partitions to fill the drive.

Be sure you have a backup (for example the original drive).
Read how to use gparted.
Boot from another drive
Unmount all partitions on the target drive
Start gparted and check that there are no lock symbols on /dev/sdb1 and /dev/sdb5.
Move /dev/sdb1 to the tail end (to the right)
Drag its left border of /dev/sdb1 to the left until the size is what you want
Drag the right border of /dev/sdb5` to the right to use all remaining unallocated drive space. The two partitions should 'touch each other'.
Check that things are as you want them.
Click on the tick icon to start the actions.
Please wait ... it will take a long time. Be sure there is enough power (do not run on battery).

If you cloned with dd you need to repair the backup partition table at the tail end of the drive with gdisk or maybe use gpt-fix.

Edit: gdisk command options cut from gpt-fix

echo \
"v
x
e
r
d
w
y" \
| gdisk "$1"

where "$1" should be replaced by the target device /dev/sdx, if run directly (not within the shellscript).

These command letters are explained in

man gdisk

The crucial commands are

in the expert's menu

   e      Move backup GPT data structures to the end of the disk. Use this
          command if you've added disks to a RAID array, thus  creating  a
          virtual  disk with space that follows the backup GPT data struc‐
          tures. This command moves the backup GPT data structures to  the
          end of the disk, where they belong.

and in the the recovery & transformation menu

   d      Use  main  GPT  header  and  rebuild  the backup. This option is
          likely to be useful if the backup GPT header has been damaged or
          destroyed.

The other commands are verifying, moving between menus and writing.

Links added by the OP, @BlueSkies:

Unable to unmount a partition with GParted - is this a problem?

GParted cannot finish step 1

GParted showing now

After cloning with mkusb, copying partitions from the original USB stick and booting from the new-larger stick, I'm unable to access the usbdata.

Please advice. Thanks!

Advice: Please post the output of the following command lines (when booted from the new-larger stick),

sudo lsblk -f
sudo lsblk -m
sudo ls -l /mountpoint-to-usbdata
sudo ls -l /mountpoint-to-casper-rw

where you enter the actual mountpoints to see usbdata and casper-rw.

This will help me understand what is the problem, so that I can suggest what to do next.

Please edit your original question to enter these output texts instead of here in my answer. Indent each line 4 characters in order to render the output as code. You can mark (high-light) the text and click on the {} icon at the head of the editing window to make those indentations quickly.

Outputs of the four above-mentioned commands:

The command sudo lsblk -f gives the following results