Just Because You Deleted A File Doesn't Mean It's Gone
I ran into a case the other day where someone was reporting an operating system bug. A filesystem was 98% full, but an examination of that filesystem showed that it should only be 25% full. It isn’t a bug. In order to understand why it isn’t, we need to know something about how files are stored, and then how they are deleted. A good place to start is the basic structure behind a UNIX-style filesystem, the inode. According to Wikipedia: an inode is a data structure on a traditional Unix-style file system such as UFS. An inode stores basic information about a regular file, directory, or other file system object… Each file has an inode and is identified by an …