Live USB with persistence vs full install on USB?

Question

I know this get asked a lot, but because things change very often with a new version of Ubuntu every 6 months, I'm curious if anything has changed regarding this question.

I'm currently using Live Ubuntu 20.10 on a 64GB USB3.1 stick with persistence. I've read on some older questions here about the same thing, and the answer is the persistence file might get corrupted easily when you install more things.

I'm gravitated towards full installation on the USB stick because of this, and also I do not need to start from fresh when a new version of Ubuntu comes out, but I'm worried that a full installation might wear out the flash on the USB much quicker because it's more optimized for a internal disk.

So the question is, will a full installation on the USB stick wears out the USB stick significantly faster than running a live USB with persistence?

Answer 1

Full Install vs Persistent install

Ubuntu can be installed to a USB in different ways. A Live install does not save between sessions. A Persistent install extracts the OS from a compressed file and saves data to an overlay file or partition each session, and a Full install installs the complete OS to the USB just like an install to internal disk.

Comparison between Persistent and Full install USB

Advantages of a persistent install:

1. You can use the persistent pendrive to install Ubuntu to another computer.

2. A persistent install takes up less space on the pendrive.

3. You can reset the pendrive by overwriting the old casper-rw file with a new one.

4. The install to pendrive takes less time.

5. Slightly less wear on the drive, however this depends on file systems, ext2 vs ext4, existence of a swapfile or partition, proper use and drive type. Many modern multi layer flash drives trade reliability for volume ie 500 writes vs 10000 to 1000000 writes. I have a couple 14 year old flash drives that I use on a daily basis, and one drive, with worn out contact points, that is still good internally. See: Lifespan a flash drive running Ubuntu?

Advantages of a Full install:

1. You can update and upgrade.

2. If you have problems or wish to modify, the solution is the same as with an internal install, (You can ask for help in the forums).

3. No ugly startup / install screen.

4. Better security, you can use full encryption

5. You can use proprietary drivers, many drivers need to start before the Persistent overlay opens therefore they do not work with a persistent install.

6. Swapfiles and partitions work and Hibernation can be enabled.

7. Many persistent installs are limited to a 4GB casper-rw and a 4GB home-rw persistence file, to get more persistence requires persistence partitions. Once casper-rw is full, the drive will not boot.

8. More efficient usage of disk space. Does not require reserved space for persistence.

9. Faster boot, no automatic disk checking or Try Ubuntu/Install Ubuntu screen.

10. You can run VBox and use virtual machines.

11. Generally faster boot than Live or Persistent USB's.

12. More stable, better for day to day use. I have run Ubuntu off a flash drive for 5 years making only LTS upgrades.

Note that once booted, both methods run at about the same speed. If the computer has lots of RAM Ubuntu should run mainly in RAM and there will not be a big difference between running off internal HDD and USB3 flash drive f.

Full Install Method

A quick and easy method to flash a Full install to USB can be found here: Easy Full Install USB that Boots both BIOS and UEFI

A more traditional methods for creating a Full install USB from scratch can be found here: How to Create a Full Install of Ubuntu 20.04 to USB Device Step by Step