I have a bootable live-USB Flash Drive with Ubuntu installed on it, it has a casper-rw for persistence, but unfortunately, the casper-rw is almost full and the remaining space for storing data is running out, I can't delete more data, Can I create another casper-rw on the same USB with a different name (such as: casper-rw 2) and mount it instead of the original one ?? and in case of that process is impossble, Can I create another casper-rw file on another USB Flash Drive, or on HDD ??

And how can I unmount the original Casper-rw (that has no additional space) , and mount the new created one? and in case of I could create two casper files on the same surface of USB Drive, (should they have different names or (it is accepted to have the same name: casper-rw)? or Should I change the name of each casper-rw file evrytime I would mount it?? (By renaming it : casper-rw and give the unmounted casper another name temporarily?


I don't think multiple overlay fs-es are what you want or need, but I think there is a solution to you space problem.

Instead of having more than one casper-rw you can extend the size of the one you already have.

Roll down to the part saying Resize an existing casper-rw loop file.

  • yes, I know that I can extend the size but in my case there is no chance to do so because my casper-rw file is already made in the max posssible size (4GB), can't be extented
    – Sarramouz
    Jul 30 '13 at 18:57
  • Unfortunaltely you will revert to the live image when unmounting the overlaying casper-rw. I'm not sure you'll be allowed to since it would be in use. Perhaps you can nest cows.
    – Sylwester
    Jul 30 '13 at 22:49

It is possible to create a new partition called casper-rw.

Then transfer your casper-rw file content using dd.

Please inform well before doing it.

And move your casper-rw file to another place.

It should work fine since it is called the same as your previous (and removed, of course) file...

You should also get informed of the better format of that casper-rw partition. But I guess that just using ext3 would work fine.

Note: When I download a new ubuntu.img I use to burn a dvd with it. Then, if I need to repair the usb pendrive, I boot with the dvd and repair everything.

Note2: I am working on another way of extending casper-rw, by creating a new partition called home-rw. Then, I should copy all my /home/ubuntu dir from my carper-rw to the new home-rw partition. And ensure that it has the same privileges that the original files. Finally, erase casper-rw's /home/ubuntu. And by doing this, getting a lot of free space for the original casper-rw.

My doubts are how to mount casper-rw for writing and transfer the data. It shouldn't be very difficult. I normally, work with mc (Midnight Commander) that makes everything very visually easy to accomplish.

I hope this helps.



You can rename a blank casper-rw file to home-rw and use it in combination with a casper-rw file for a total of 8GB. In this case the casper-rw is similar to a "/" partition in a Full install and the home-rw file is similar to a "/home" partition in a Full install.

I usually use casper-rw and home-rw partitions in my persistent flash drives. Rough benchmarking shows no difference in speed from using casper-rw and home-rw files.

Edit 2017 Following question asks about multiple casper-rw partitions but explains how to use multiple casper-rw files: MultiBoot with Multiple Persistent partitions

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