Inodes

https://www.howtogeek.com/465350/everything-you-ever-wanted-to-know-about-inodes-on-linux/ https://metebalci.com/blog/a-minimum-complete-tutorial-of-linux-ext4-file-system/

inodes are a data structure of POSIX File Systems (notably the ext family, e.g. ext4) that describe a File or Directory on disk

The inode stores metadata such as access permissions and modified/created dates, allocated disk blocks

inodes are stored in an inode table, which are referenced from the Block Group Descriptor Table

An inode with no Hard Links is considered an orphan

File Areas

Files may be split over different physical blocks on disk. In older filesystems (e.g. ext3), inodes would contain a reference to one more more blocks for each block in a file; for very large or fragmented files, those blocks would contain further pointers to other blocks

In later systems (e.g. ext4), this system has changed to use Extents, which are capable of recording just the start and end blocks for each contiguous area containing the file