I have just noticed that casper-rw persistent files are not working with Ubuntu 20.04 when booted from an ISO file.
Persistent partitions are again working, however persistent partitions do not work with "persistent-path" and only one persistent partition is allowed per USB drive.
This means that a multiboot, multipersistence USB drive is no longer possible using ISO files.
I have also just tested BIOS and UEFI boot modes of a Persistent UNetbootin USB drive and persistence does not seem to be working with Syslinux either.
Hopefully someone will point out where I am making an error, or show how to fix this problem.
Reference: How do I boot an ISO file from my drive using grub2 on UEFI machines?
Bug Report: https://bugs.launchpad.net/ubuntu/+source/grub2/+bug/1877222
casper-rw is now writable
The persistent file/partition name in Ubuntu 20.04 has been officially changed from
casper-rw
towritable
.On my computer a persistent partition can be named either
casper-rw
orwritable
and it will still work.However a persistent file must now be named
writable
.On a persistent 20.04 drive made with Unetbootin, changing
casper-rw
towritable
will also fix persistence.One Live USB expert compared this to America changing the name of the dollar to "valuable".