7
I'm confused by this. My understanding is that a live CD is sometimes accessed through the ISO 9660 driver (like when you're accessing the file without booting), but obviously a different filesystem is used when the system is booted up. Let's take for example a Linux Live CD with the Ext3 filesystem that is to be accessible by Windows when not booting. When Windows accesses it, it needs to have some kind of formatting that Windows can read; I assume this would be ISO 9660. But to be bootable, the partition needs to be formatted as a Linux filesystem. How can a partition be formatted as both an ISO 9660 filesystem and a Linux filesystem? I know there's something fundamental that I'm getting wrong here, but this isn't the sort of question you can just Google and expect to get an answer.
Zen Hacker
Posted 2018-07-28T00:07:02.107
Reputation: 353
3Actually, it would theoretically be possible for two filesystems to share the same space. As long as the metadata doesn't collide (for example, if one filesystem stores its metadata at a fixed address at the beginning and the other at a variable address at the end), then they can share the raw file data, and mark the metadata area of the respective other filesystem as unused space. Obviously, this only works for read-only file systems. I don't know whether this would work for ISO9660 and Ext4, for example, but it could theoretically work. – Jörg W Mittag – 2018-07-28T07:28:55.653
3In fact, this is how the UDF Bridge format works, where a UDF file system and an ISO9660 file system share the same physical medium. – Jörg W Mittag – 2018-07-28T07:35:54.027