Those are not separate drives. They are probably partitions on your thumb drive. To check this, open your terminal in Ubuntu and type (as sudo):
ASMT109x - Config is a Windows USB device driver.
Regarding the "2GB Loop"...
https://unix.stackexchange.com/quest...on-to-bootable
filesystem.squashfs contains the entire system, in a compresed image format.
Squashfs is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes up to 1 MB for greater compression. Several compression algorithms are supported. Squashfs is also the name of free software, licensed under the GPL, for accessing Squashfs filesystems.
https://en.wikipedia.org/wiki/SquashFS
Squashfs is intended for general read-only file-system use and in constrained block-device memory systems (e.g. embedded systems) where low overhead is needed.
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Hope that helps. By the way, this information was readily available via search engine. When you're wondering about things like this, a quick search on your fav search engine will usually bring up numerous hits that will help answer your questions.
Regards and have a great week!
~Eric