Comment 5 for bug 1708881

I should add to the previous comment, that hybrid iso files are made to be *cloned* to USB drives (and memory cards) to make boot drives. The cloning process is very robust and likely to succeed. For this reason the Ubuntu Startup Disk Creator was revamped from a bug-ridden extracting tool to a simplified and robust cloning tool. The new version was introduced with Ubuntu 16.04 LTS.

There are cases when you want to use a USB pendrive both as a live drive and a storage device. This does not work with the read-only iso 9660 file system. In these cases you can use another tool, an extracting tool to create a persistent live drive.