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I was reading this guide to installing Ubuntu on a flash drive to see if there are any new ways of making a persistent boot, but I had a couple of questions.

I like this method bc I can have several operating systems plus my files on a drive, and don't have to dedicate a whole drive to an OS. Is there a way to introduce a persistent memory onto this?

The other question I have is, if I do the Unetbootin method, usb-creator, or pen drive linux, am I able to update my flash drive OS and keep it updated or will I have to get updates every time?

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The linked site links against another site for the actual instructions, and that site is offline. It can be found here:… – noleti Aug 2 '14 at 0:51
up vote 1 down vote accepted

You can do a few Full installs to separate partitions on the pendrive with various o/s and each will retain modifications.

If you want to do a few persistent, (Frugal), installs, the persistence mechanism needs to be different, as with Ubuntu, Puppy, Debian, etc.

Do not try to share a casper-rw file between different 'buntus, things will go really wonky.

Suggest only include the word "persistent" in the menuentry of the one 'buntu in grub.cfg you want persistent.

Let me know if you need clarification.

I suggest not trying to do a software update with a persistent install, when you fill casper-rw the drive will not boot. Also you can not upgrade the kernel of a persistent install.

I use the MultiBootUSB script to boot multiple o/s iso's on USB using grub2. I have had both Ubuntu and Puppy working persistently. Had no luck with Debian persistence.

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For your first question: Yes. The easiest is probably to use Unetbootin or usb-creator. For Unetbootin, turn the "Space used to preserve files across reboots (Ubuntu only)" option to something more than 0. For usb-creator, the slider near the bottom is the measure. If you prefer to roll your own grub config, the boot option is "persistent" and there must be a file or partition somewhere with a filesystem on it called "casper-rw".

For the second: Treat it like another computer. When you boot it up, install the updates, just like you would any other computer. You will need ~1-4GB of space for persistence for it to work, or else you will run out of space (you will eventually anyway, just be prepared).

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Sorry, for the first question I meant is there a way to add persistent memory if I set it up manually the way they show in that section, without unetbootin or pendrivelinux. – JFA Apr 19 '14 at 16:49
Yes, it is possible. In the menu.lst, on the line that starts with kernel, and before the -- (if its there), add persistent rw. And then create the casper-rw filesystem. – user269370 Apr 19 '14 at 22:22

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